IS there a way to know what fonts will work? I can get a few locally installed fonts to work, but most don’t seem to.
None that I know of, sorry. Most of the fonts work for me (I'm on Mac). As far as I remember, all the fonts I downloaded from Google Fonts work fine. In some cases when a font doesn't work, the problem seems to be in its name: it should be entered in the generator differently than it looks in system tools.