Smart Button to trigger a specific song to play on a specific google home speaker

Hi,

I’ve managed to sync my smart button to play/pause a track that’s already playing on a specific google home speaker. But I’m looking to use the button to trigger my kid’s bed time song (on spotify) that plays on repeat all night long at a low volume. Any help would be appreciated.

PS - It doesn’t have to be spotify. If doing it on YT music or Apple music is easier on HA, that would work too.

THanks!