2ndSVGarage.yaml

#Something like this:
cover:
  - platform: mqtt
    name: "First Garage"
    state_topic: "cmnd/2/POWER2" #type "SwitchTopic2 2" in the Tasmota Console
    command_topic: "cmnd/FirstGarage/POWER" #your Sonoff name would be "FirstGarage"
    payload_open: "ON"
    payload_close: "ON"
    payload_stop: "ON"
    state_open: "ON"
    state_closed: "OFF"
    optomistic: false
    retain: false
  - platform: mqtt
    name: "Second Garage"
    state_topic: "cmnd/3/POWER2" #type "SwitchTopic2 3" in the Tasmota Console
    command_topic: "cmnd/SecondGarage/POWER" #your Sonoff name would be "SecondGarage"
    payload_open: "ON"
    payload_close: "ON"
    payload_stop: "ON"
    state_open: "ON"
    state_closed: "OFF"
    optomistic: false
    retain: false

#in "Customize.yaml" or customize section of config.yaml:
cover.first_garage:
  device_class: garage
  friendly_name: My Garage
cover.second_garage:
  device_class: garage
  friendly_name: Wife Garage

#in "Groups.yaml" or groups section of config.yaml:
    garage_doors:
      name: Garage Doors
      view: no
      control: hidden
      icon: mdi:garage
      entities:
        - cover.first_garage
        - cover.second_garage
# with Lovelace I'm not sure you even need the customize and groups sections anymore. You can do it with the Customization menu in HA Configuration tab and Lovelace now