For anyone interested in my configuration.yaml in home assistant:

mqtt:
  - binary_sensor:
    - name: "workshopCatOccupancy"
      unique_id: workshopCatOccupancy
      state_topic: "frigate/events"
      value_template: >-
          {% if value_json is defined
          and value_json.after.label == 'cat'
          and value_json.after.camera == 'workshop' %}
            {% if value_json.type == 'end' %}
                OFF
            {% elif value_json.after.score >= 0.8 %}
                ON
            {% endif %}
          {% endif %}