How to enable H264 for Firefox?

I noticed that AlmaLinux 8.10 lacks the packages mozilla-openh264 and it's prerequisite openh264, and that both are absent from official repositories too. To my knowledge, I need these both in order to be able to play H264 videos on Firefox, like on https://udemy.com . I downloaded the packages from these URLs: 1. https://rhel.pkgs.org/8/raven-multimedia-x86_64/openh264-2.4.1-2.el8.x86_64.rpm.html 2. https://rhel.pkgs.org/8/raven-multimedia-x86_64/mozilla-openh264-2.4.1-2.el8.x86_64.rpm.html Then installed them with: sudo rpm -i .rpm I also activated the H264 plugin on about:addons. But still, about:support points H264 as not supported. What am I missing?