I have ankidroid in French but sync error message in English.
It would be very nice if you could add an optional parameter to the sync request with the locale, so that we can provide you the language, and we get a translated message. I guess using existing translation tools should work.
Relatedly, I really think this message should have a URL as I doubt many people recall what ankiweb is. I’d even state it would be nice to have an extra value in the sync error message you sent that provides a URL so that the different platform can offer a button to directly open the url for the users, to simplify their flowpath
