Brightness slider for Loverace light card

I need your advice on the brightness slider for the Lovelace light card.
I have an infrared controlled LED ceiling light and the control in Home Assistant is using the smart infrared remote controller API.
This light is at maximum brightness when turned on and the brightness can be changed in 6 levels.
The brightness is controlled by input_number and automation, and I would like to integrate this with template light, but the brightness slider does not show up on the Lovelace light card.
I would like to ask you to point out if there is any mistake in my light settings.

My native language is not English, so I apologize if my English is poor.

input_number:
  light_brightness:
    name: light_brightness
    min: 0
    max: 8
    mode: slider
light:
  - platform: template
    lights:
      study_light:  
        value_template: "{{ states('input_boolean.light_study') }}"
        level_template: "{{ states('input_number.light_brightness') }}"
        turn_on:
          - service: rest_command.light_study_on
          - service: input_boolean.turn_on
            entity_id: input_boolean.light_study
          - service: input_number.set_value
            target:
              entity_id: input_number.light_brightness
            data:
              value: 8
        turn_off:
          - service: rest_command.light_study_off
          - service: input_boolean.turn_off
            entity_id: input_boolean.light_study
          - service: input_number.set_value
            target:
              entity_id: input_number.light_brightness
            data:
              value: 0
automation:
  - id: ' '
    alias: brightness down
    description: ''
    trigger:
    - entity_id: input_number.light_brightness
      platform: state
    condition:
    - condition: numeric_state
      entity_id: input_number.light_brightness
      above: '0'
    - condition: state
      entity_id: light.study_light
      state: 'on'
    action:
    - repeat:
        count: '{{ trigger.from_state.state|int - trigger.to_state.state|int }}'
        sequence:
        - delay:
            hours: 0
            minutes: 0
            seconds: 0
            milliseconds: 250
        - service: rest_command.light_study_brightness_down
    mode: single

  - id: ' '
    alias: brightness up
    description: ''
    trigger:
    - platform: state
      entity_id: input_number.light_brightness
    condition:
    - condition: numeric_state
      entity_id: input_number.light_brightness
      below: '8'
    - condition: state
      entity_id: light.study_light
      state: 'on'
    action:
    - repeat:
        count: '{{ trigger.to_state.state|int - trigger.from_state.state|int }}'
        sequence:
        - delay:
            hours: 0
            minutes: 0
            seconds: 0
            milliseconds: 250
        - service: rest_command.light_study_brightness_up
    mode: single