Sonos_say example script fails

I am trying out the sonos_say example script from here. I have copied and pasted the script into my configuration.yaml with the only change is that I am using service: tts.google_translate_say.

In my ui-lovelace.yaml I have added an entity button to be able to call the script.

      - type: entity-button
        entity: person.emil
        tap_action:
          action: call-service
          service: script.sonos_say
          data:
            sonos_entity: media_player.kitchen
            volume: 0.50
            message: 'Testing!'
            delay: '00:00:05'

However, when I click on the entity-button in Lovelace, I get a notification in the down left corner saying:

"Failed to call service script/sonos_say. not a valid value for dictionary value @ data['entity_id']"

If I go into the script and change “{{ sonos_entity }}” to media_player.kitchen, the notification instead says

"Failed to call service script/sonos_say. expected float for dictionary value @ data['volume_level']"

So if I in the script change:

"{{ volume }}" to 0.5
"{{ message }}" to "Test"
"{{ delay }}" to '00:00:05'

and then click on the entity-button, it all works! So my guess here is that there is something with the way I pass the arguments to the script.

Can somebody help me to figure out what I am doing wrong?