Question about Pro 920 Duo - 81011

Hello
I couldn't get it to work, but didn't want to spend a lot of time on it.
For me, it looked like the base station could only be looped into the receiver of a landline phone and the Bluethooth connection between the headset and the base station was working.
the Bluethooth connection between the headset and this base station works or can be set up.

Also Bluetooth ja also pc smartphone tablett .............