Gas meter total - set initial value

Configuration
1

Hi all,

I have recently added a gas meter addition (reed sensor as a pulse) but now I’m stuck on how to show the physical meters total rather than the total since the sensor went in.

I have read various posts saying to add the “initial” value but I’m lost as to where and how to do that. On my dashboard it shows like this:

image

And so i would like to see the “gas-meter Gas Meter - Total” show the actual reading on the physical meter.

sensor:
  - platform: pulse_meter
    pin: 
      number: D6
      mode: INPUT_PULLUP
    internal_filter: 400ms
    name: "Gas Meter - Consumption"
    filters:
      - multiply: 0.06
    unit_of_measurement: "m³/ min"
    id: gas
    accuracy_decimals: 2
    icon: 'mdi:fire'
    total:
      name: "Gas Meter - Total"
      state_class: total_increasing
      device_class: gas
      unit_of_measurement: "m³"
      accuracy_decimals: 2
      filters:
        - lambda: return x * (1.0 / 100);

Just not sure exactly how to get started or where to add that “starting” value

Thanks,
David