There’s also this, one for Firefox, but if you use Firefox on Android, you’ll need to get Firefox Nightly (Google Play)
Or this if you use F-droid.
It’s based on Firefox and allows you to install addons without using the Nightly version
Yes. Just like with Fennec F-Droid and Firefox Nightly, you can install any extension by following these steps: https://www.ghacks.net/2020/10/01/you-can-now-install-any-add-on-in-firefox-nightly-for-android-but-it-is-complicated/