Connecting RAMSES RF to RAMSES-ESP Path Error

Hardware
1

Have connected RAMSES-ESP and connected to internet.
Have installed RAMSES RF via HACS and configured via config flow
Have tried a variey of Serial Port Addresses always the error
Unrecoverable problem with the serial port: Unable to open the serial port: portaddress
Any suggestions?
Many thanks.

2

I suggest you ask on the ramses rf GitHub page.

Also that repo refers you to this Honeywell CH/DHW via RF - evohome, sundial, hometronics, chronotherm