Rest command with templated body

i’m using the following:

  input_number:
    mopidy_volume:
      name: 'Mopidy Volume'
      min: 0
      max: 100
      step: 1

  rest_command:
    mopidy:
      url: http://192.168.0.186:6680/mopidy/rpc
      method: POST
      payload: '{{ body }}'
      content_type:  'application/json'
      timeout: 10

  automation:
  - alias: Mopidy Volume
    initial_state: 'on'
    trigger:
      platform: state
      entity_id: input_number.mopidy_volume
    action:
      - service: rest_command.mopidy
        data_template:
          body: '{"method": "core.playback.set_volume","jsonrpc": "2.0","params": {"volume": {{states("input_number.mopidy_volume")}} },"id": 1}'

moving the input_number slider isn’t setting the volume (i see no errors but it doesn’t work).
if i replace {{states(“input_number.mopidy_volume”)}} with a static 90, moving the slider executes the command successfuly and the volume is being set to 90.

what am i missing here?

did you get it working?