6. Seriously, why not Ubuntu Focal on Raspberry Pi 4 ? - HaroldSP/Harold GitHub Wiki

Ubuntu Focal

The general installation process is shown on that video. Here are some useful commands and tips to navigate in your new system:

Get the information about your GPU memory:

grep -i --color memory /var/log/Xorg.0.log

Output:

[    40.249] (II) FBDEV(0): hardware: simple (video memory: 8100kB)