ESPhome Use MQTT payload in lambda

Hi, I would like to use the message payload to set the value of a servo motor over mqtt.

I found this in the documentation but couldn’t get it right. The mqtt part of my esphome config:

mqtt:
  broker: 
  username: 
  password: 
  id: esp32
  on_message:
    topic: servo/input
    qos: 0
    then:
      - servo.write:
          id: pillangoszelep
          level: !lambda |-

Does anyone have any suggestions?
Thanks

This seems like a straight scenario. Strange that there no one else is doing this