Having trouble with MQTT HVAC

I have upgrades from a very old HA and having trouble setting up my mqtt hvac thermostat.
I get the reading from a sensor in my Livingroom, and turning on a relay to turn my heat on. But I can not get it to come on when I raise the temperature I’m missing something but can not figure out what.

  - platform: mqtt
    name: Study
      - "off"
      - "cool"
      - "fan_only"
      - "on"
      - "off"
      - "high"
      - "medium"
      - "low"
    power_command_topic: "study/ac/power/set"
    mode_command_topic: "study/ac/mode/set"
    temperature_command_topic: "cmnd/furnace/POWER"
    current_temperature_topic: "Home/LivingRoom/temp"
    fan_mode_command_topic: "study/ac/fan/set"
    swing_mode_command_topic: "study/ac/swing/set"
    precision: 1.0

I’m not sure if the cmnd/furnace/POWER is in the right place I tried all, when I put it in the power_command_topic: the relay will turn on when I turn on the heat, but will not when raising the temperature. hope some one can help me see what I’m missing. Thanks

I put the Code in the brackets but it said it still wasn’t.

NO one can Help?