Ubuntu 22.04 forces Firefox snap, even if you don't want to use it.
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 install firefox