Hi again,
downloaded the current DietPi_RPi-ARMv7-Buster_AlloGUI.7z unpacked and worte it to a sd.
Modified the dietpi.txt for WiFi boot but turns out there is no dietpi-wifi.txt in /boot/ of the sd.
Hi,
many thanks for your message. Indeed the file is missing on the image.
MichaIng : can you have a look. Probably the image would need to be recreated
Ah makes sense since it is a pre-installed image. Actually this means that dietpi-wifi.txt would not even have an effect, none of the firstrun/automation settings (aside of file system expansion and swap file creation) are executed.
Mid-term we need to change the way how pre-installed images are created, so that all firstrun setup steps are executed but only a different set of software titles/packages is pre-installed, but I just reviewed and updated the AlloGUI images recently (Fourdee created and maintained those previously) the first time and left things as they are for now.
So this means currently you need an Ethernet connection or local console access to configure WiFi via dietpi-config.
or to flash a new Allo image and before first boot, transfer dietpi-wifi.txt from normal RPi image 
It does not have an effect. dietpi-wifi.txt is only automatically applied (respectively WiFi enabled, based on dietpi.txt) when dietpi-firstboot.service runs, and that is not enabled on the Allo GUI images. I think it would break some configs, generally the firstboot/setup scripts might not handle pre-installed software gracefully, override configs and such, which is the reason support for this kind of pre-installed images needs to be implemented from the ground up.
ah ok. thx for clarification.