HUGE thanks to @ioannis for this since he figured out a fix.
The mp3 binary was tricky and I had been trying to get this to work using the base64 string that Google Cloud’s text-to-speech API returns but I hadn’t had any luck.
@ioannis used Any Component blocks to set the sound source and play the sound:
Initially, those blocks looked like they were from a StP project but they aren’t; they are from DnD. Specifically, they are these two blocks:
It would be great to also figure out how to play the mp3 file. This method doesn’t seem to work for that whether I set the sound source to the green response block or get object from JSON [response].