How can you use template in a lovelace service call?

1

This code:

state_color: true
title: var.
type: entities
entities:
  - entity: var.feeder_boost_timer
  - type: divider
  - type: call-service
    action_name: Start boost
    icon: 'mdi:cat'
    name: Feeder Boost XXX seconds
    service: script.start_feeder_timer
    service_data:
      seconds: XXX

gives me this:
image

However, I’d like to have the XXX show the value of the variable. The following template has the value:

{{ states.var.feeder_boost_timer.state | int }}

I can’t figure out how to put that value in for the seconds and name fields.

Is this possible?