Hi @brucehvn , I was in the same boat as you 10 minutes ago.
It seems there was a problem with Google TTS platform but it has been solved in 0.83.2 as confirmed in this thread.
I didn’t want to update to a new version yet so I applied the patch mentioned here.
The next step was to enter in the developers tools this JSON (no message inside data, just message alone):
{"entity_id": "media_player.upstairs", "message":"testing one, two, three"}
and everything was fine. Good luck!