Alexa media player and FireTVs

I’ve discovered the notify.alexa_media_last_called feature and fell in love. I did notice that it doesn’t seem to recognize this function on my FireTV’s. Is this just the way things are or am I missing something. This is all I’m trying to do. It’s working just fine on my echos.

    - service: notify.alexa_media_last_called
        message: (my message)
          type: tts