When I click the add-on button I get a banner "fxtranslation-notification" and that's it.

There is zero information about how this should be used.

I'm surprised the option page does not offer to set the supported languages.

Оффлайновый смешной потраченный перевод

Fantastic idea but needs some polish. Would like to use it for words and selected text passages as well.

Plugin doesn't work.
UI is anti-intuitive and freezing