Did you follow all the steps on the Github Readme? The addon is a couple of years old, hasn’t been updated for a couple of years. Maybe it’s outdated and doesn’t work any longer.
You do have the Comfoair integration running? See:
This card is relying on this integration to function.
Allright. I am not familiar with Comfoair equipment. With a quick look it seems to me that you need to have the “ComfoConnect LAN C Internet interface” for the integration to work. Do you have that lan interface?
The Esphome solution in that github repo, seems a more DIY solution in which you connect the device to an ESP device without the LAN interface, if I am correct.
I think both are different approaches of hooking up the Comfoair to Home Assistant.
I dont have a lan interface , its not available for my zehnder whr950, that why i went with the esphome solution and the lovelace card witch are both mentioned at mr wichers github, these two are supposed to work together.