Question about use of value variable in value_template

Hi,
unfortunately, despite reading several previous topics posted here, I do not really understand how the “value” variable works in value_templates.

I have configured the following browser_mod card as a service:

service: browser_mod.popup
data:
  content:
    type: custom:vacuum-card
    entity: vacuum.valetudo_roborock
    image: default
    stats:
      default:
        - entity_id: sensor.valetudo_roborock_main_brush
          value_template: "{{ (value | float(0) / 3600) | round(1) }}"
          unit: hours
          subtitle: Main brush
        - entity_id: sensor.valetudo_roborock_right_brush
          value_template: "{{ (value | float(0) / 3600) | round(1) }}"
          unit: hours
          subtitle: Right brush
        - entity_id: sensor.valetudo_roborock_main_filter
          value_template: "{{ (value | float(0) / 3600) | round(1) }}"
          unit: hours
          subtitle: Main filter
        - entity_id: sensor.valetudo_roborock_sensor_cleaning
          value_template: "{{ (value | float(0) / 3600) | round(1) }}"
          unit: hours
          subtitle: Sensors
      cleaning:
        - entity_id: sensor.valetudo_roborock_current_statistics_area
          value_template: "{{ (value | float(0) / 3600) | round(1) }}"
          subtitle: Cleaned Area
          unit: m2
        - entity_id: sensor.valetudo_roborock_current_statistics_time
          value_template: "{{ (value | float(0) / 60) | round(1) }}"
          unit: minutes
          subtitle: Cleaning Time
    shortcuts:
      - name: Clean Selection
        service: script.vacuum_clean_segments
        icon: mdi:floor-plan

It worked well when I triggered it as a button from the GUI. Now I have moved the code to a script (for various reasons), but get the “UndefinedError: ‘value’ is undefined” error when I execute it.

What am I doing wrong?

Home Assistant version, browser_mod, cards etc are all up-to-date.

While trying to keep the post small, I hope I still posted all required information.