Firefox should have asked if you wanted to import your stuff from t.o.b.*.
Caveat: I know it does if that other browser is IE. Whether it does if t.o.b.* is Edge I don’t know.
Suggestion: If you remember being asked about importing stuff when you installed it, and since you haven’t really gotten too much stuff into FF yet, try uninstalling FF and reinstalling it to get a second shot at answering those questions..
(*That Other Browser)
It did, but all it imported was my documents, and not the Favorites. (You’re ahead of me, I see... ;o])
And FYI: My FF is as long as two pieces of string.