Open extensions on Firefox for Android debut December 14 (but you can get a sneak peek today):

Starting December 14, 2023, extensions marked as Android compatible on addons.mozilla.org (AMO) will be openly available to Firefox for Android users.

But not of course for iOS, because Apple doesn’t allow companies to use any rendering engine other than Safari’s webview. And Apple also hates the idea of extensions that aren’t themselves applications, so don’t expect them to make the lives of extension developers easy once the EU forces them to open things up a little.