Install Firefox (22.04)

Ubuntu 22.04 forces Firefox snap, even if you don't want to use it.
The below method also works on WSL (Windows).

First, remove the snap version of Firefox:

sudo snap remove firefox

Add the official Mozilla Team PPA:

sudo add-apt-repository ppa:mozillateam/ppa

To make sure the system always uses the Mozilla Team PPA, you need to set its priority.
Open this file:

Add this text:

Package: firefox*
Pin: release o=LP-PPA-mozillateam
Pin-Priority: 501

Finally, update and install.

apt update
apt install firefox