Pop!_OS 20.04: Fix Most Videos Not Playing In Firefox

On a fresh Pop!_OS 20.04 installation, users may be taken by sursprise by the fact that most videos from streaming websites don't work in Firefox. This article explains how to fix this.

Video not playing in Firefox on Pop!_OS 20.04

If you've just installed Pop!_OS 20.04 and try to play some videos in Firefox, you'll notice that YouTube works, but for most other websites, like Twitch, Netflix, Dailymotion, Vimeo, and so on, playing videos doesn't work (even gifv files on Reddit, gfycat and Imgur).