Qundis heat meter read optical interface (HMR5)

I am living in a rent apartment with such a heat meter. I am looking for a solution to read data from the optical bus. I have used optical interfaces for engergy meters, but need the protocol for the heat meter.

Qundis itself is not willing to help end-users, they only offer support their direct customers.

You might check if this device supports wireless m-bus. Then with an extra USB antenna you will be able to receive packets. Assuming that device uses encrypted communication, you still will need to obtain encryption key to decode actual payload.