nixCraft published a guide about installing LXD on Ubuntu 20.04 LTS using apt.
Install LXD on Ubuntu 20.04 LTS using apt
Explains how to install, configure, and set up LXD based containers on Ubuntu 20.04 LTS to move your VMs straight to containers & run various Linux distros.
Install LXD on Ubuntu 20.04 LTS using apt - nixCraft