Install Ubuntu 22.04 on an SSD drive

Use Raspberry Pi Imager from Raspberry Pi Software to install the operating system on the USB disk
To enable remote desktop run:
sudo apt install xrdp
sudo systemctl enable --now xrdp
For some reason I don't understand to get remote desktop working you have to disable wayland in /etc/gdm3/custom.conf:
WaylandEnable=false
Getting sound to work using remote desktop is a challenge, see links.

Some links:

Enabling sound via xRDP