With these steps I managed to get Pimox on my Raspberry Pi 4 and 5 in february 2024.
Check the comments for usage at a later date, namely: https://gist.github.com/enjikaka/52d62c9c5462748dbe35abe3c7e37f9a?permalink_comment_id=6429742#gistcomment-6429742
Install "RPi OS Lite 64-bit" with Raspberry Pi Imager. It's listed under "Raspberry Pi OS (Other)"