Ubuntu 20.04: Via: https://www.raspberrypi.org/downloads/ – go down to “Third Party Operating System Images” and download Ubuntu Server. Once booted, use “Desktopify” as shown in the video to add a graphical desktop, and note that the code at 11:02 is:
sudo ./desktopify --de ubuntu
What I type in the video is correct, but in the caption I missed out the ./ before desktopify. Sorry!