Sonos Set Sleep Timer

I’m a total noob at HA… currently confused by the way syntax needs to be and struggling to get the Sonos Sleep Timer Setup.

Using this in scripts

sonos_sleep:
  - service: media_player.Sonos_Set_Sleep_Timer
      entity_id: media_player.portable
      sleep_time: 0

and getting the follow error
2018-04-25 17:43:17 ERROR (SyncWorker_0) [homeassistant.util.yaml] mapping values are not allowed here
in “/config/scripts.yaml”, line 34, column 16
2018-04-25 17:43:17 ERROR (MainThread) [homeassistant.bootstrap] Error loading /config/configuration.yaml: mapping values are not allowed here
in “/config/scripts.yaml”, line 34, column 16

Can anyone suggest what i’m doing wrong here?

Maybe

  - service: media_player.sonos_set_sleep_timer
    data_template:
      entity_id: media_player.portable
      sleep_time: 0