Play two Echo devices at same time?

I have a Gen 4 Dot and Echo Show 5 that I would like to have play music on both of them at the same time. I can control them separately to play music and TTS,so things work the way they should.

Do I need to create a custom card?

You could put them in a group, in the alexa app. Then play music on that group.

I have them in a group in the Alexa app and I can play them both if using the App. They just don’t both play in at the same time in HA. I guess I need to create a group in HA.