Help for smart button + timer code

Configuration
1

Hello everybody
I made a card with a timer and its power button, and this works … Now I want to add a smart button, but I can’t enter the code, kindly someone could help me.

Thank you

immagine

this is the code used:

homeassistant:

input_number:  
  minuti_luci:
    name: Minuti Timer Luci
    initial: 1
    min: 1
    max: 20
    step: 1
    icon: mdi:timer

timer:
  light_on:
    name: Timer Luci

automation:
  - alias: Luci accese timer acceso
    trigger:
      platform: state
      entity_id:
        - switch.switch_pompa_di_ricircolo
      to: 'on'

    action:
      service: timer.start
      entity_id: timer.light_on
      data_template:
        duration: "{{ (states('input_number.minuti_luci')|int(2) * 60)|timestamp_custom('%H:%M:%S',false) }}"

  - alias: Luci spente timer cancellato
    trigger:
      platform: state
      entity_id:
        - switch.switch_pompa_di_ricircolo
      to: 'off'

    action:
      service: timer.cancel
      entity_id: timer.light_on

  - alias: Luci spente fine timer
    trigger:
      platform: event
      event_type: timer.finished
      event_data:
        entity_id: timer.light_on
    action:
      service: switch.turn_off
      data_template:
        entity_id: 
          - switch.switch_pompa_di_ricircolo