Calculate Energy Consumption per Month / SolaX/QCells HYB-G3

hi all,
i was looking for an option to let HA calculate the house’ energy consumption in kWh.
i googled a lot but did not find a suitable solution
what i have done so far:

-created a helper based on “Riemann Sum Integral”
-created a helper “Utility Meter”
-created a utility_meter on yaml

however the first ones do not show the kWh. last one creates an error message

i have solaX / QCells HYB G3, and installed SolaX inverter ModBus (all values are received)

i tried to use sensor.solax_house_load, which acutally shows the “real time” consuption of the house.

yaml gets the following error (i tried daily, monthly is the target):
Invalid config for [utility_meter]: [consumption_house_day_kWh] is an invalid option for [utility_meter]. Check: utility_meter->utility_meter->consumption_house_day_kWh.

utility_meter:
consumption_house_day_kWh:
source: sensor.solax_house_load
cycle: daily
name: consumption_house_day_kWh

any ideas to easy calculate the energy consumption per month?

anyone any idea???