Manual input of meter reading in Energy dashboard

Hi everyone,
I am trying to setup a couple of input_number entities for manually* grabbing the values of the gas and water meter in my home.

So far I have:

  1. set up a input_number helper : input_number.gas_reading
    this contains the always-increasing read value from the meter
  2. set up a sensor template to turn the input_number in a sensor (to be fed into the utility meter entity in step 3)
  template:
  - sensor:
    - name: 'Gas reading sensor'
      unit_of_measurement: 'm³'
      state: >
        {{ '%4.4f'%states('input_number.gas_reading') | float }}
      state_class: total_increasing
      unique_id: 'gas_reading_sensor'
      device_class: 'gas'
  1. created a utility meter to generate a daily usage sensor.gas_daily_consumption as I understand it’s needed to be accepted by the Energy Dashboard

Now, when I try to add this sensor to the Energy Dashboard, it simply does not appear in the list.
I can instead add sensor.
gas_reading_sensor, however I am not sure if this is what is supposed to be entered in the Energy dashboard.
I can see that sensor.gas_daily_consumption has statistics, so I don’t understand why the Energy dashboard does not accept it.

Can someone see what am I doing wrong?

*well, semi manually since I use iOS shortcuts to OCR the read value and submit it to HA.
I cannot use any HW to automate because the counter are in a shared space in my apartment building and don’t have any network/power there.

No it is not required. You can use your sensor.

Utility meters are useful for converting an always increasing value to hourly/daily/monthly/etc… totals.

The energy dashboard can work with always increasing sensors.

Thanks! that’s useful to know!

One more thing: can I avoid setting up the template :

template:
  - sensor:
    - name: 'Gas reading sensor'
      unit_of_measurement: 'm³'
      state: >
        {{ '%4.4f'%states('input_number.gas_reading') | float }}
      state_class: total_increasing
      unique_id: 'gas_reading_sensor'
      device_class: 'gas'

and instead use a helper?

I am afraid that with the helper I cannot set up the state_class and device_class which I think are needed by the energy dashboard (again, read in some previous thread, not sure if this is still true)

That is correct. So you need the template sensor.