Response error: 500 Saving Script

Is me

getting this error when I try to save a script

and the Yaml is

alias: Cast Bike to Garage TV
icon: mdi:television-classic
sequence:
  - service: cast.show_lovelace_view
    data:
      entity_id: media_player.garage_tv
      dashboard_path: lovelace
      view_path: bike
mode: single

what manual did I miss reading.