Edit. 5 stars again after the fix
I use it for the opposite of what it should do. Basically I hate the AI autodubbing new thing on YouTube, I'm Italian but I know English, I don't need and I don't want the videos to be autodubbed in a strange Italian with a different voice from the original author of the video, and even when I don't know the language I still want to hear the original voice and only use the subtitles translation. I also cannot stand ads so I use YouTube mobile version on Firefox with ublock origin so I cannot use the app.
This extension works to restore the original dub and silence the translated dub on Firefox mobile website (where there is no option at all).
Not sure if the author of this extension intended this since it seems to be born to do the opposite but it's still 5 stars for me.
I suggest the author of this plugin to just put an option without any other configurations for those that will use the app like me and add this possibility in the description of this extensions, I'm not the only one that hate YouTube forcing the AI auto dubbing thing.