TTS Cloud say script not working

I created a script for Google Assistant to answer a question (via routines → scenes in the Google home app) based on a text input helper i created, but it is not working. The assistant answers that the device is not available.

The script look like this:

alias: "Hebben de vissen gegeten-google assistant "
sequence:
  - service: tts.cloud_say
    data:
      entity_id: media_player.drakenhol_wekker
      message: "{{state ('input_text.vissen_google_assistant_antwoord')}}"
mode: single

This is the standard script HA creates when you use the visual editor for the tts.

I reckon there should probably be a data_template somewhere, but can’t figure out where. I tried it on a couple of places in the script (don’t know where anymore), but all did not work. What am i doing wrong?