The Guided Installation (grommunio Appliance) instructions talk about downloading an ISO file but when I download the Raspberry Pi appliance, I have a .raw.xz file. I have used Rufus (on Windows) and dd on Linux to create what I hoped would be a bootable USB stick. I have tried both the original .xz file and the .raw file after extracting.
I have a Raspberry Pi 5, which boots successfully from an NVMe drive. I have adjusted the boot order to try USB first, then NVMe, then SD card. However, in all four of the above cases, I see my Raspberry Pi 5 try unsuccessfully to boot from the USB stick before moving on in the boot order.
What am I doing wrong? How do I create a bootable USB stick from the .raw.xz file?