After several years of Plex music not working on the Amazon Tap (1st generation rechargable Echo-type device, discontinued), I absentmindedly told it "Ask Plex to play [a song in my library], and to my surprise, it worked!
Evidently, Amazon got around to updating the Tap’s firmware. There had been an expired Let’s Encrypt certificate baked in. It had been fixed for all other 1st gen Alexa devices about 2 years ago.
I had been using the Emby skill with the Tap to get a similar, though not as flexible functionality.
I will keep using the Tap until its built-in battery goes south, and will probably try to replace the battery if/when that happens.
Hooray!
