Help with syntax

Configuration
1

I created a template in my configuration.yaml file, but I am now getting errors about syntax. The template is designed to trigger an event at a random time between 11:15pm and 11:50pm. The error I get is “string does not match the pattern of legacy syntax” on the two platform lines. Can someone assist with correcting the error:

template:
  - trigger:
      - platform: time
        at: '23:00:00'
      - platform: event
        event_type: event_template_reloaded
    sensor:
      - name: Random Start Time between 23h15 and 23h50
        unique_id: 'midnight_actions-random_time'
        state: "{{ (today_at('23:15:00') + timedelta(minutes = range(0,36) | random)).isoformat() }}"
        device_class: timestamp
2

Replace platform by trigger and you should be fine.
Is Home Assistant complaining, or just Studio Code? The old format should still work.