Linux Shout published a tutorial about installing Docker on Ubuntu 20.04.
Best way to install Docker on Ubuntu 20.04 Linux
Learn the best way to install Docker engine CE on Ubuntu Hirsute 21.04, Groovy 20.10, Ubuntu Focal 20.04 (LTS), and Bionic 18.04 (LTS).
Best way to install Docker on Ubuntu 20.04 Linux