USB Install on Pi 4

Good evening!

I am fairly new and am trying to install dietpi to a USB drive for use with a Pi4 8gb. I know the Pi3B+ will boot to USB natively, but I cant seem to find a how-to for the Pi4 without installing to a microSD card first. Is it possible to install directly to the USB drive?

Thanks in advance!

There is no need for a how-to. Just flash the image to your USB disks and boot from it. Usually RPi4 support usb ootb.

To be sure you could install it once on SD card to have the bootloader updated.

OK. I tried on a different Pi4 and I just got flashing green light and no boot. I will try again later to see I need to update the boot loader. I assume if I do it to microSD, I can get to the boot from section to designate boot from USB? Or maybe not needed once the first boot is done?

just have a look to RPi documentation

a minimum bootloader version is needed. Usually the bootloader will be updated by DietPi installation process during first setup.

Another possibility is to change boot order
BOOT_ORDER fields would need to be set to 0x4

For both you could boot from SD card

you could use RPI imager as well to change boot mode