Starting a Spotify Playlist on Chromecast

Hi All,
I installed the binding (2.4) without any hitch, I can read all the values from the Thing, and I can discover any devices that Spotify streams to.

Unfortunately, I can’t seem to control my Spotify account.

I have a:
Bridge @ spotify_player_Paul_trackPlayer, and a
Device @ spotify_device_Paul_3c3c_devicePlayer

I try this in my Rule:

        sendCommand(spotify_device_Paul_3c3c_trackPlay, "spotify:user:spotify:playlist:37i9dQZF1E358oZ9hslUxp")
        sendCommand(spotify_player_Paul_trackPlay, "spotify:user:spotify:playlist:37i9dQZF1E358oZ9hslUxp")
        sendCommand(spotify_device_Paul_3c3c_devicePlayer, "PAUSE")
        sendCommand(spotify_player_Paul_trackPlayer, "PAUSE")

But it does nothing.

When I manipulate Spotify on my phone, it changes the Items appropriately.

I should also note, that I only have the free Spotify. Do you need the Premium?