Monthly rates in energy cost calculation

Hi,

I can setup energy cost calculation based on current consumption multiplied with cost per kWh. My real energy cost includes an additional monthly rate, so in sum I have to pay monthly

rate_per_kwh * monthly_kwh_value + monthly_base_rate

Is it possible to create a sensor that outputs this value?

The method used by @gdesfeux worked well for me, give that a try
Energy Dashboard - How to add monthly electricity subscription? - Configuration - Home Assistant Community (home-assistant.io)