MQTT payload problem

1

hi i have a mqtt light the value of payload are like this payload off - “R13_ON” payload on “R13_OFF” bright ness topic - “Dimmer:” (followed by value i.e 1-90) eg Dimmer:40 make little dim Dimmer: 90 is full brightness i have tried various ways to make the dimmer work but it doesn’t

please help

light:
  - platform: mqtt
    name: "test light"
    command_topic: "sub"
    payload_on: "R13_ON"
    payload_off: "R13_OFF"
    brightness_command_topic: "Dimmer:"
    brightness_scale: 90