AI being what it is, at this point you might be able to ask it for a token to put in a web page at .well-known, put it in as requested, and let it see it, and that might actually just work without it being officially built in.

I suggest that because I know for sure the models can hit the web; I don't know about their ability to do DNS TXT records as I've never tried. If they can then that might also just work, right now.