Telegram commands and text

I’ve been working with telegram bot, mainly just to see what I can do as I am quite new to this all. I got it working so that I can issue a command to turn my lights on/off but now I’d like to issue the same command followed by a percentage to make it dim. My current code looks like this:

# Turn on lights via chatbot
- id: chatbot_lights_on
  alias: 'Chatbot lights on'
  trigger:
    platform: event
    event_type: telegram_command
    event_data:
      command: '/lights_on'
  action:
    service: light.turn_on
    entity_id: group.all_lights

Is there a feature for including a variable that I can then pass through?

If it won’t work with lights my other thought was making writing a command and text that would then be spoken by google tts through my speaker.

Any help would be greatly appreciated!