I love the extension. It completely improves the YT experience.
I'd tried other options, and they didn't work quite right.

Does not work at all in Firefox for Android. Also the name of the addon has a misspelled word.

mein tag ist gerettet danke danke

Still not perfect, but much better than having to search for autogenerated subtitles in the YT settings. Thanks

no function

I don't show its Settings Icon ....
Tested on:
Firefox Quantum and Warefox Classic

just working