Hello Celticbeachfront,
If you're unable to play audio from Apple Music on your HomePod, let's start by making sure Apple Music is selected as the default music service on HomePod:
You can set a default music service on HomePod so that you don’t have to say the name of the service (Spotify, for example) when you ask Siri to play something. You can still play music from other supported services that you add to HomePod too by saying the name of the service when you make your Siri request.
1. In the Home app, tap
, then tap Home Settings.
Note: If you have more than one home, you see settings for your current home (based on your location). To edit a different home, tap Homes, then tap the home you want to edit.
2. Tap your user profile under People.
3. Under Media, tap the music service you want to set as your default service.
You can also change which user account should be used when someone’s voice isn’t recognised. In the Home app on your iOS or iPadOS device, touch and hold a HomePod, scroll down, tap
, then tap Primary User.
You'll find more information here: Play audio using Siri on HomePod
Cheers.