How to make kiosk mode work?

I would like to run chromium kiosk mode on dietpi within my proxmox environment.

First I did a clean install of dietpi with all updates. Then I added chromium via dietpi-software and set it to autostart.

After reboot I got an error.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
 ─────────────────────────────────────────────────────
 DietPi v10.0.1 : 18:25 - Sa 14.02.2026
 ─────────────────────────────────────────────────────
 - Device model : Container (x86_64)
 - CPU temp : 16 °C / 60 °F : Who put me in the freezer!
 - LAN IP : 192.168.200.211 (eth0)
 - WAN IP : 2a00:6020:...
 ─────────────────────────────────────────────────────

 dietpi-launcher : All the DietPi programs in one place
 dietpi-config   : Feature rich configuration tool for your device
 dietpi-software : Select optimised software for instalation
 htop            : Resource monitor
 cpu             : Shows CPU information and stats


X.Org X Server 1.21.1.16
X Protocol Version 11, Revision 0
Current Operating System: Linux KazBot 6.17.4-2-pve #1 SMP PREEMPT_DYNAMIC PMX 6.17.4-2 (2025-12-19T07:49Z) x86_64
Kernel command line: BOOT_IMAGE=/boot/vmlinuz-6.17.4-2-pve root=UUID=148a3a09-70d1-4f16-bdc3-0817b92b9e97 ro rootflags=degraded
xorg-server 2:21.1.16-1.3+deb13u1 (https://www.debian.org/support) 
Current version of pixman: 0.44.0
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Sat Feb 14 18:25:22 2026
(==) Using config directory: "/etc/X11/xorg.conf.d"
(==) Using system config directory "/usr/share/X11/xorg.conf.d"
(EE) 
Fatal server error:
(EE) no screens found(EE) 
(EE) 
Please consult the The X.Org Foundation support 
         at http://wiki.x.org
 for help. 
(EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
(EE) 
(EE) Server terminated with error (1). Closing log file.
xinit: giving up
xinit: unable to connect to X server: Connection refused
xinit: server error

When trying to start chromium I get an error of course

root@KazBot:~# chromium --kiosk
[1117:1117:0214/183511.813292:ERROR:ui/ozone/platform/x11/ozone_platform_x11.cc:256] Missing X server or $DISPLAY
[1117:1117:0214/183511.813323:ERROR:ui/aura/env.cc:257] The platform failed to initialize.  Exiting.

Ok, because my first intention was to use xrdp I installed xrpd too
apt install xrdp xorgxrdp

xrdp requires to modify startwm.sh or ~/.xsession to start chromium instead of a wm

root@KazBot:~# cat /home/dietpi/.xsession
#!/bin/bash
# Start Chromium in Kiosk Mode
# chromium --kiosk --no-first-run --noerrdialogs --disable-infobars --remote-debugging-port=9222 --user-data-dir=/home/dietpi/Kleinanzeigen/ https://kleinanzeigen.de &
chromium --kiosk --start-fullscreen https://kleinanzeigen.de &

When establishing the connection vis xrdp / xorg I get the same error as before

root@KazBot:/home/dietpi# cat .xsession-errors 
Xsession: X session started for dietpi at Sa 14. Feb 17:51:31 CET 2026
dbus-update-activation-environment: setting DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
dbus-update-activation-environment: setting DISPLAY=:10.0
localuser:dietpi being added to access control list
[3564:3564:0214/175131.364872:ERROR:ui/ozone/platform/x11/ozone_platform_x11.cc:256] Missing X server or $DISPLAY
[3564:3564:0214/175131.364891:ERROR:ui/aura/env.cc:257] The platform failed to initialize.  Exiting.

The session request looks ok

root@KazBot:/var/log# cat xrdp-sesman.log 
[2026-02-14T17:33:05.420+0100] [INFO ] starting xrdp-sesexec with pid 2698
[2026-02-14T17:33:05.481+0100] [INFO ] TerminalServerUsers group tsusers doesn't exist. Access granted for dietpi
[2026-02-14T17:33:05.481+0100] [INFO ] Access permitted for user: dietpi
[2026-02-14T17:33:05.493+0100] [INFO ] Starting X server on display 10: /usr/lib/xorg/Xorg :10 -auth .Xauthority -config xrdp/xorg.conf -noreset -nolisten tcp -logfile .xorgxrdp.%s.log 
[2026-02-14T17:33:06.496+0100] [INFO ] X server :10 is working
[2026-02-14T17:33:06.496+0100] [INFO ] Starting window manager for display :10
[2026-02-14T17:33:06.496+0100] [INFO ] Using the default window manager on display 10: /etc/xrdp/startwm.sh
[2026-02-14T17:33:06.497+0100] [INFO ] Starting the xrdp channel server for display :10
[2026-02-14T17:33:06.497+0100] [INFO ] Session in progress on display :10. Waiting until the window manager (pid 2711) exits to end the session
[2026-02-14T17:33:06.525+0100] [INFO ] Window manager (pid 2711, display 10) finished normally in 0 secs
[2026-02-14T17:33:06.525+0100] [WARN ] Window manager (pid 2711, display 10) exited quickly (0 secs). This could indicate a window manager config problem
[2026-02-14T17:33:06.525+0100] [INFO ] Terminating X server (pid 2702) on display :10
[2026-02-14T17:33:06.525+0100] [INFO ] Terminating the xrdp channel server (pid 2713) on display :10
[2026-02-14T17:33:06.526+0100] [INFO ] xrdp channel server pid 2713 on display :10 finished
[2026-02-14T17:33:06.531+0100] [INFO ] X server pid 2702 on display :10 finished

xorg log, look fine too

root@KazBot:/home/dietpi# cat .xorgxrdp.10.log 
[1098429.498] 
X.Org X Server 1.21.1.16
X Protocol Version 11, Revision 0
[1098429.498] Current Operating System: Linux KazBot 6.17.4-2-pve #1 SMP PREEMPT_DYNAMIC PMX 6.17.4-2 (2025-12-19T07:49Z) x86_64
[1098429.498] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-6.17.4-2-pve root=UUID=148a3a09-70d1-4f16-bdc3-0817b92b9e97 ro rootflags=degraded
[1098429.498] xorg-server 2:21.1.16-1.3+deb13u1 (https://www.debian.org/support) 
[1098429.498] Current version of pixman: 0.44.0
[1098429.498]   Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
[1098429.498] Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[1098429.498] (++) Log file: ".xorgxrdp.10.log", Time: Sat Feb 14 17:51:30 2026
[1098429.498] (++) Using config file: "/etc/X11/xrdp/xorg.conf"
[1098429.498] (==) Using config directory: "/etc/X11/xorg.conf.d"
[1098429.498] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[1098429.498] (**) Option "defaultserverlayout" "X11 Server"
[1098429.498] (**) ServerLayout "X11 Server"
[1098429.498] (**) |-->Screen "Screen (xrdpdev)" (0)
[1098429.498] (**) |   |-->Monitor "Monitor"
[1098429.498] (**) |   |-->Device "Video Card (xrdpdev)"
[1098429.498] (**) |-->Input Device "xrdpMouse"
[1098429.498] (**) |-->Input Device "xrdpKeyboard"
[1098429.498] (**) Option "DontVTSwitch" "on"
[1098429.498] (**) Option "AutoAddDevices" "off"
[1098429.498] (**) Option "AutoAddGPU" "off"
[1098429.498] (**) Allowing byte-swapped clients
[1098429.498] (**) Not automatically adding devices
[1098429.498] (==) Automatically enabling devices
[1098429.498] (**) Not automatically adding GPU devices
[1098429.498] (==) Automatically binding GPU devices
[1098429.498] (==) Max clients allowed: 256, resource mask: 0x1fffff
[1098429.498] (WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist.
[1098429.498]   Entry deleted from font path.
[1098429.498] (WW) The directory "/usr/share/fonts/X11/100dpi/" does not exist.
[1098429.498]   Entry deleted from font path.
[1098429.498] (WW) The directory "/usr/share/fonts/X11/75dpi/" does not exist.
[1098429.498]   Entry deleted from font path.
[1098429.498] (WW) The directory "/usr/share/fonts/X11/Type1" does not exist.
[1098429.498]   Entry deleted from font path.
[1098429.498] (WW) The directory "/usr/share/fonts/X11/100dpi" does not exist.
[1098429.498]   Entry deleted from font path.
[1098429.498] (WW) The directory "/usr/share/fonts/X11/75dpi" does not exist.
[1098429.498]   Entry deleted from font path.
[1098429.498] (==) FontPath set to:
        /usr/share/fonts/X11/misc,
        built-ins
[1098429.498] (==) ModulePath set to "/usr/lib/xorg/modules"
[1098429.498] (**) Extension "DPMS" is disabled
[1098429.498] (II) Loader magic: 0x58a213855f00
[1098429.498] (II) Module ABI versions:
[1098429.498]   X.Org ANSI C Emulation: 0.4
[1098429.498]   X.Org Video Driver: 25.2
[1098429.498]   X.Org XInput driver : 24.4
[1098429.498]   X.Org Server Extension : 10.0
[1098429.499] (II) systemd-logind: took control of session /org/freedesktop/login1/session/c16
[1098429.500] (II) xfree86: Adding drm device (/dev/dri/card0)
[1098429.500] (II) Platform probe for /sys/devices/pci0000:00/0000:00:08.1/0000:08:00.0/drm/card0
[1098429.500] (EE) systemd-logind: failed to take device /dev/dri/card0: Operation not permitted
[1098429.506] (--) PCI:*(8@0:0:0) 1002:1638:1458:d000 rev 201, Mem @ 0xffe0000000/268435456, 0xfff0000000/2097152, 0xfce00000/524288, I/O @ 0x0000e000/256
[1098429.506] (II) "glx" will be loaded. This was enabled by default and also specified in the config file.
[1098429.506] (II) LoadModule: "dbe"
[1098429.506] (II) Module "dbe" already built-in
[1098429.506] (II) LoadModule: "ddc"
[1098429.506] (II) Module "ddc" already built-in
[1098429.506] (II) LoadModule: "extmod"
[1098429.506] (II) Module "extmod" already built-in
[1098429.506] (II) LoadModule: "glx"
[1098429.506] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
[1098429.506] (II) Module glx: vendor="X.Org Foundation"
[1098429.506]   compiled for 1.21.1.16, module version = 1.0.0
[1098429.506]   ABI class: X.Org Server Extension, version 10.0
[1098429.506] (II) LoadModule: "int10"
[1098429.506] (II) Loading /usr/lib/xorg/modules/libint10.so
[1098429.506] (II) Module int10: vendor="X.Org Foundation"
[1098429.507]   compiled for 1.21.1.16, module version = 1.0.0
[1098429.507]   ABI class: X.Org Video Driver, version 25.2
[1098429.507] (II) LoadModule: "record"
[1098429.507] (II) Module "record" already built-in
[1098429.507] (II) LoadModule: "vbe"
[1098429.507] (II) Loading /usr/lib/xorg/modules/libint10.so
[1098429.507] (II) Module int10: vendor="X.Org Foundation"
[1098429.507]   compiled for 1.21.1.16, module version = 1.0.0
[1098429.507]   ABI class: X.Org Video Driver, version 25.2
[1098429.507] (II) LoadModule: "glamoregl"
[1098429.507] (II) Loading /usr/lib/xorg/modules/libglamoregl.so
[1098429.508] (II) Module glamoregl: vendor="X.Org Foundation"
[1098429.508]   compiled for 1.21.1.16, module version = 1.0.1
[1098429.508]   ABI class: X.Org ANSI C Emulation, version 0.4
[1098429.508] (II) LoadModule: "xorgxrdp"
[1098429.508] (II) Loading /usr/lib/xorg/modules/libxorgxrdp.so
[1098429.508] (II) Module XORGXRDP: vendor="X.Org Foundation"
[1098429.508]   compiled for 1.21.1.11, module version = 0.10.2
[1098429.508]   ABI class: X.Org Video Driver, version 25.2
[1098429.508] xorgxrdpSetup:
[1098429.508] (II) LoadModule: "fb"
[1098429.508] (II) Module "fb" already built-in
[1098429.508] (II) LoadModule: "xrdpdev"
[1098429.508] (II) Loading /usr/lib/xorg/modules/drivers/xrdpdev_drv.so
[1098429.508] (II) Module XRDPDEV: vendor="X.Org Foundation"
[1098429.508]   compiled for 1.21.1.11, module version = 0.10.2
[1098429.508]   ABI class: X.Org Video Driver, version 25.2
[1098429.508] xrdpdevSetup:
[1098429.508] (II) LoadModule: "xrdpmouse"
[1098429.508] (II) Loading /usr/lib/xorg/modules/input/xrdpmouse_drv.so
[1098429.508] (II) Module XRDPMOUSE: vendor="X.Org Foundation"
[1098429.508]   compiled for 1.21.1.11, module version = 0.10.2
[1098429.508]   Module class: X.Org XInput Driver
[1098429.508]   ABI class: X.Org XInput driver, version 24.4
[1098429.508] rdpmousePlug:
[1098429.508] (II) LoadModule: "xrdpkeyb"
[1098429.508] (II) Loading /usr/lib/xorg/modules/input/xrdpkeyb_drv.so
[1098429.509] (II) Module XRDPKEYB: vendor="X.Org Foundation"
[1098429.509]   compiled for 1.21.1.11, module version = 0.10.2
[1098429.509]   Module class: X.Org XInput Driver
[1098429.509]   ABI class: X.Org XInput driver, version 24.4
[1098429.509] rdpkeybPlug:
[1098429.509] rdpIdentify:
[1098429.509] (II) XRDPDEV: driver for xrdp: XRDPDEV
[1098429.509] rdpDriverFunc: op 10
[1098429.509] (WW) Falling back to old probe method for XRDPDEV
[1098429.509] rdpProbe:
[1098429.509] (II) Loading sub module "fb"
[1098429.509] (II) LoadModule: "fb"
[1098429.509] (II) Module "fb" already built-in
[1098429.509] rdpProbe: found DRMDevice xorg.conf value [/dev/dri/renderD128]
[1098429.509] rdpProbe: found DRI3 xorg.conf value [1]
[1098429.509] rdpProbe: found DRMAllowList xorg.conf value [i915 radeon]
[1098429.509] (II) XRDPDEV(0): using default device
[1098429.509] (WW) VGA arbiter: cannot open kernel arbiter, no multi-card support
[1098429.509] rdpPreInit:
[1098429.509] rdpPreInit: /dev/dri/renderD128 open failed
[1098429.509] (**) XRDPDEV(0): Depth 24, (--) framebuffer bpp 32
[1098429.509] (==) XRDPDEV(0): RGB weight 888
[1098429.509] (==) XRDPDEV(0): Using gamma correction (1.0, 1.0, 1.0)
[1098429.509] (==) XRDPDEV(0): Default visual is TrueColor
[1098429.509] (==) XRDPDEV(0): DPI set to (96, 96)
[1098429.509] (II) XRDPDEV(0):  mode "640x480" ok
[1098429.509] (II) XRDPDEV(0):  mode "800x600" ok
[1098429.509] (II) XRDPDEV(0): Virtual size is 800x600 (pitch 800)
[1098429.509] (**) XRDPDEV(0):  Default mode "800x600": 36.0 MHz (scaled from 0.0 MHz), 35.2 kHz, 56.2 Hz
[1098429.509] (II) XRDPDEV(0): Modeline "800x600"x0.0   36.00  800 824 896 1024  600 601 603 625 +hsync +vsync (35.2 kHz d)
[1098429.509] rdpScreenInit: virtualX 800 virtualY 600 rgbBits 8 depth 24
[1098429.509] rdpScreenInit: pfbMemory bytes 1920000
[1098429.509] rdpScreenInit: pfbMemory 0x7144881e5010
[1098429.509] rdpSimdInit: assigning yuv functions
[1098429.509] rdpSimdInit: cpuid ax 1 cx 0 return ax 0x00a50f00 bx 0x0a0c0800 cx 0x7ef8320b dx 0x178bfbff
[1098429.509] rdpSimdInit: sse2 amd64 yuv functions assigned
[1098429.509] (==) XRDPDEV(0): Backing store enabled
[1098429.509] rdpClientConInit: disconnect idle session after [0] sec
[1098429.509] rdpClientConInit: kill disconnected [0] timeout [0] sec
[1098429.509] rdpXvInit: depth 24
[1098429.509] rdpScreenInit: out
[1098429.509] (II) Initializing extension Generic Event Extension
[1098429.509] (II) Initializing extension SHAPE
[1098429.509] (II) Initializing extension MIT-SHM
[1098429.509] (II) Initializing extension XInputExtension
[1098429.509] (II) Initializing extension XTEST
[1098429.509] (II) Initializing extension BIG-REQUESTS
[1098429.509] (II) Initializing extension SYNC
[1098429.509] (II) Initializing extension XKEYBOARD
[1098429.509] (II) Initializing extension XC-MISC
[1098429.509] (II) Initializing extension SECURITY
[1098429.509] (II) Initializing extension XFIXES
[1098429.510] (II) Initializing extension RENDER
[1098429.510] (II) Initializing extension RANDR
[1098429.510] (II) Initializing extension COMPOSITE
[1098429.510] (II) Initializing extension DAMAGE
[1098429.510] (II) Initializing extension MIT-SCREEN-SAVER
[1098429.510] (II) Initializing extension DOUBLE-BUFFER
[1098429.510] (II) Initializing extension RECORD
[1098429.510] (II) Initializing extension Present
[1098429.510] (II) Initializing extension DRI3
[1098429.510] (II) Initializing extension X-Resource
[1098429.510] (II) Initializing extension XVideo
[1098429.510] (II) Initializing extension XVideo-MotionCompensation
[1098429.510] (II) Initializing extension SELinux
[1098429.510] (II) SELinux: Disabled on system
[1098429.510] (II) Initializing extension GLX
[1098429.510] (II) AIGLX: Screen 0 is not DRI2 capable
[1098429.527] (II) IGLX: Loaded and initialized swrast
[1098429.527] (II) GLX: Initialized DRISWRAST GL provider for screen 0
[1098429.527] (II) Initializing extension XFree86-VidModeExtension
[1098429.527] (II) Initializing extension XFree86-DGA
[1098429.527] (II) Initializing extension XFree86-DRI
[1098429.527] (II) Initializing extension DRI2
[1098429.527] rdpCreateScreenResources:
[1098429.539] (II) Using input driver 'XRDPMOUSE' for 'xrdpMouse'
[1098429.539] (**) Option "CorePointer"
[1098429.539] (**) xrdpMouse: always reports core events
[1098429.539] rdpmousePreInit: drv 0x58a2165ebd10 info 0x58a2166d34e0, flags 0x0
[1098429.539] (II) XINPUT: Adding extended input device "xrdpMouse" (type: Mouse, id 6)
[1098429.539] rdpmouseControl: what 0
[1098429.539] rdpmouseDeviceInit:
[1098429.539] rdpmouseCtrl:
[1098429.539] rdpRegisterInputCallback: type 1 proc 0x7144888974f0
[1098429.539] (**) xrdpMouse: (accel) keeping acceleration scheme 1
[1098429.539] (**) xrdpMouse: (accel) acceleration profile 0
[1098429.539] (**) xrdpMouse: (accel) acceleration factor: 2.000
[1098429.539] (**) xrdpMouse: (accel) acceleration threshold: 4
[1098429.539] rdpmouseControl: what 1
[1098429.539] rdpmouseDeviceOn:
[1098429.539] (II) Using input driver 'XRDPKEYB' for 'xrdpKeyboard'
[1098429.539] (**) Option "CoreKeyboard"
[1098429.539] (**) xrdpKeyboard: always reports core events
[1098429.539] rdpkeybPreInit: drv 0x58a2165ec450 info 0x58a216893f50, flags 0x0
[1098429.539] (II) XINPUT: Adding extended input device "xrdpKeyboard" (type: Keyboard, id 7)
[1098429.539] rdpkeybControl: what 0
[1098429.539] rdpkeybDeviceInit:
[1098429.546] rdpkeybChangeKeyboardControl:
[1098429.546] rdpkeybChangeKeyboardControl: autoRepeat on
[1098429.546] rdpRegisterInputCallback: type 0 proc 0x7144883bba30
[1098429.546] rdpkeybControl: what 1
[1098429.546] rdpkeybDeviceOn:
[1098429.572] (II) config/udev: Adding drm device (/dev/dri/card0)
[1098429.572] (II) xfree86: Adding drm device (/dev/dri/card0)
[1098429.572] (II) Platform probe for /sys/devices/pci0000:00/0000:00:08.1/0000:08:00.0/drm/card0
[1098429.572] (EE) systemd-logind: failed to take device /dev/dri/card0: Operation not permitted
[1098429.579] rdpDeferredRandR:
[1098429.579] rdpResizeSession: width 1024 height 768
[1098429.579]   calling RRScreenSizeSet
[1098429.579] rdpRRScreenSetSize: width 1024 height 768 mmWidth 271 mmHeight 203
[1098429.579] rdpRRGetInfo:
[1098429.579]   screen resized to 1024x768
[1098429.580]   RRScreenSizeSet ok 1
[1098429.580] rdpResizeSession: width 800 height 600
[1098429.580]   calling RRScreenSizeSet
[1098429.580] rdpRRScreenSetSize: width 800 height 600 mmWidth 212 mmHeight 159
[1098429.580] rdpRRGetInfo:
[1098429.580]   screen resized to 800x600
[1098429.581]   RRScreenSizeSet ok 1
[1098429.581] rdpRRSetRdpOutputs: numCrtcs 0 numOutputs 0 monitorCount 0
[1098429.581] rdpRRSetRdpOutputs: update output 0 left 0 top 0 width 800 height 600
[1098429.581] rdpRRConnectOutput:
[1098429.647] rdpInDeferredRepeatCallback:
[1098429.647] rdpkeybChangeKeyboardControl:
[1098429.647] rdpkeybChangeKeyboardControl: autoRepeat off
[1098430.497] rdpRRGetInfo:
[1098430.500] rdpClientConGotConnection:
[1098430.500] rdpClientConGotConnection: g_sck_accept ok new_sck 9
[1098430.500] rdpClientConGetConnection: idle_disconnect_timeout set to non-positive value, idle timer turned off
[1098430.500] rdpAddClientConToDev: adding first clientCon 0x58a216ad5fa0
[1098430.500] rdpClientConProcessMsgVersion: version 0 0 0 1
[1098430.500] rdpClientConProcessMsgClientInput: invalidate x 0 y 0 cx 800 cy 600
[1098430.500] KbdSync: toggling num lock
[1098430.500] rdpkeybChangeKeyboardControl:
[1098430.500] rdpkeybChangeKeyboardControl: autoRepeat off
[1098430.529] rdpmouseControl: what 2
[1098430.529] rdpmouseDeviceOff:
[1098430.529] rdpkeybControl: what 2
[1098430.529] rdpkeybDeviceOff:
[1098430.529] xorgxrdpDamageDestroy:
[1098430.530] rdpkeybControl: what 3
[1098430.530] rdpkeybUnInit: drv 0x58a2165ec450 info 0x58a216893f50, flags 0x0
[1098430.530] rdpUnregisterInputCallback: proc 0x7144883bba30
[1098430.530] rdpmouseControl: what 3
[1098430.530] rdpmouseUnInit: drv 0x58a2165ebd10 info 0x58a2166d34e0, flags 0x0
[1098430.530] rdpUnregisterInputCallback: proc 0x7144888974f0
[1098430.530] rdpCloseScreen:
[1098430.530] xorgxrdpDownDown:
[1098430.530] xorgxrdpDownDown: 1
[1098430.530] rdpClientConDeinit:
[1098430.530] rdpClientConDeinit: disconnecting clientCon
[1098430.530] rdpClientConDisconnect:
[1098430.530] rdpRemoveClientConFromDev: removing clientCon 0x58a216ad5fa0
[1098430.530] rdpClientConDeinit: deleting file /run/xrdp/sockdir/1000/xrdp_display_10
[1098430.530] rdpClientConDeinit: deleting file /run/xrdp/sockdir/1000/xrdp_disconnect_display_10
[1098430.531] (II) Server terminated successfully (0). Closing log file.

How to go on, to get it work?

Do you have a screen or console attached? Kiosk is not working via SSH. Maby this is specific to Proxmox and how it is setup. Which user you used while selecting Chromium as autostart option (dietpi-autostart)?

I just tested it on a regular SBC RPi4B and it’s working (after applying a known workaround Error running Chromium in kiosk mode · Issue #7923 · MichaIng/DietPi · GitHub )

I guess you would need to install a desktop in addition, like LXDE. I recommend using dietpi-software to install xrdp (software option 29)