Sending media to cast devices

I am having trouble trying to get my google home ‘media_player’'s play music from an automation. I would like to use any of the follow streams; https://radio.abc.net.au/help/streams

Right now my automation looks like this:

- alias: 'dining light on play classical'
  trigger:
    - platform: state
      entity_id: switch.diningroom_switch_2
      to: 'on'
  condition:
    - condition: and
      conditions:
        - condition: time
          after: "18:00:00"
        - condition: time
          before: "22:00:00"
    # seems to run twice in a row
    - condition: template
      value_template: '{{ trigger.from_state.state != trigger.to_state.state }}'
    - condition: state
      entity_id: vacuum.terry
      state: 'off'
    - condition: state
      entity_id: input_boolean.zwave_up
      state: 'on'
  action:
    - service: media_player.play_media
      data:
        entity_id: media_player.living_room_speaker
        media_content_id: "http://www.abc.net.au/res/streaming/audio/mp3/classic_two.pls"
        media_content_type: 'audio/mp3'
    # set the volume
    - service: input_number.set_value
      entity_id:
        - input_number.google_home
      data_template:
        value: 40

The documentation is lacking on what you can do with cast devices or are they just the same as plain media players and that is it?

Right now that automation when it triggers, I get a peep from my google home and no music.

THanks

hello,
try this
media_content_type: music

That does not looked to have helped, any other ideas?

it seems the stream I am using does not work.

ok, so https://radio.abc.net.au/help/streams

these pls files are not supported… thye are text files holding other metadata including the direct URL which works.