Sonos Symfonisk Button

Hello fellow builders,

I’m trying to make something fairly simple, but still can’t get my head around because there is so much information.

What i’m trying:
I have 2 sonos speakers (IKEA Symfonisk. Great stuff. Fair price)
I have 3 favorites in my sonos account

I installed Mini Media Player and would like to have configured like this:
Five would be my first favorite
Six would be my second
Seven would be my third

I’ve enabled the favorites entity in Home Assistant that’s disabled by default, and the entity has 3 items.

I had created something that i hoped it might work, but it’s not…

type: custom:mini-media-player
entity: media_player.sonos_symfonisk
group: false
source: full
  columns: 4
    - name: SLAM! Summer
        action: call-service
        service: media_player.select_source
          source: SLAM!
          device_id: 4dd57468b219981f723998e1ebaf2845