HA heater automation help for Roy

roy_heater_ex1.yaml

alias: 'Heat on when close to home'
description: Turn on heat when Roy is leaving work on his way home.
trigger:
  - platform: zone
    entity_id: device_tracker.roy
    zone: zone.work
    event: leave
condition:
  - condition: state
    entity_id: proximity.roy_home
    state: towards
    attribute: dir_of_travel
action:
  - condition: state
    entity_id: binary_sensor.people_home
    state: 'off'
  - service: HOWEVER YOU TURN ON YOUR HEATER    
mode: single