It is possible that your Linux distribution is no longer supported with update (i.e. is EOL). If that is the case then you can possibly install Firefox from the Mozilla server since you currently appear to be using the version from the Ubuntu repositories.

• https://www.mozilla.org/en-US/firefox/all/#product-desktop-release

You can Verify that you meet the System Requirements (GTK+ and GLib) for the current Firefox release.

• https://www.mozilla.org/en-US/firefox/98.0.1/system-requirements/

Also just to be sure you can fully support HTML5 players used for videos, audio and even games on websites around like Youtube and Twitch, make sure you have packages like FFmpeg installed.