Here’s a command that works for me to queue up a playlist on Spotify with Google Home Assistant:

OK Google Shuffle <name of playlist> Playlist

I also included this one on a routine called “Best of” where it fires up the TV, switches to the Chromecast (which are connected to some Sonos gear) and modified the command to use the Chromecast:

OK Google Shuffle <name of playlist> Playlist on the Chromecast

This puts the spotify (my music service) app up on the TV with the playlist name and current song showing.

Let me know in the comments if you got this working, or have found additional interesting ways to automate your life!!