Long answer: if you want to use Firefox you’ll have to find an unsupported way of running it. Chromium is also a snap in the repositories ( it is a meta package)
I’ve had a good experience with setting up the Brave repository from the official website and using that.
Live patch is a commercial product and I don’t think many home users of Ubuntu use it.
If doing a fresh install is viable for you, I recommend PopOS 22.04 they ship and support their own build of Firefox as a native package and flatpak and flathub are configure out of the box and are preferable to snaps (but not forced on you)