Call service - timer duration set

Hi to everybody,
I need a help to configure a call service tab in order to properly set the timer duration variables.

I have two input_number and i need that the difference between this two state become the duration of one timer (already created on HASS)

The automation.yaml is this:

- id: '511_1'
  alias: Living Room Front - Set Position Down
    platform: state
    entity_id: input_number.livingfront_set_position
    condition: template
    value_template: >-
        {{ (states.input_number.livingfront_position.state | int) >
           (states.input_number.livingfront_set_position.state | int) }}
  - service: timer.start
      entity_id: timer.livingfront_down
      duration: >-
          {{ '00:00:%02d' | format(((
              (states.input_number.livingfront_position.state | int) - 
              (states.input_number.livingfront_set_position.state | int)
             ) * 21 /100) | int | abs )

I think that the main problem is that the call service tab don’t accept the data_template set but only data entry

In the call service node with the same duration template mark check the " Use alternative template tags for the Data field" option. Check if it works, otherwise i would use a jsonata expression

Did you get it working in node-red?