Home Assistant Automation Blueprint for syncing the states of two lights

sync_lights.yaml

blueprint:
  name: Sync two lights
  description: Turn on a light when other one is turend on and vice versa
  domain: automation
  input:
    light_entity1:
      name: Light 1
      selector:
        entity:
          domain: light
    light_entity2:
      name: Light 2
      selector:
        entity:
          domain: light
variables:
  light_entity1: !input light_entity1
  light_entity2: !input light_entity2
trigger:
  - platform: state
    entity_id: 
      - !input light_entity1
      - !input light_entity2
    from: 'on'
    to: 'off'
  - platform: state
    entity_id: 
      - !input light_entity1
      - !input light_entity2
    from: 'off'
    to: 'on'
action:
  service_template: >
    {% if trigger.to_state.state == 'on' %}
    light.turn_on
    {% elif trigger.to_state.state == 'off' %}
    light.turn_off
    {% endif %}
  data_template: 
    entity_id: >
      {% if trigger.from_state.entity_id == light_entity1 %}
      {{ light_entity2 }}
      {% elif trigger.from_state.entity_id == light_entity2 %}
      {{ light_entity1 }}
      {% endif %}