If you happened to see a “sudo: add-apt-repository: command not found” error when typing sudo add-apt-repository command, then you need to install the software-properties-common package by typing the following:
sudo apt-get install software-properties-common python-software-properties
This error typically happens when you try to add a PPA to install any program that’s not in the official repositories in Ubuntu.
Further Reading
Ubuntu Linux Unleashed 2021 Edition (14th Edition)
The Linux Command Line: A Complete Introduction (2nd Edition)
How Linux Works: What Every Superuser Should Know (3rd Edition)
