Hi,
Bluetooth was originally designed as a close proximity networking technology. Bluetooth 5.0 has newer technology to increase the transmission/reception range .
The B2 can't recognise or work with Bluetooth 5.0 dongles so you have to connect to a Bluetooth 5.0 range extender using one of the other B2 outputs,
i.e. speaker connections, line out or spdif optical out.
My search of the forum posts has not uncovered details of an extender device that someone has used successfully, and I have no direct experience with an extender so can't really recommend one, but points to think about:
1. Not all Bluetooth 5.0 extenders are created equal - I have read wildly varying distance claims for the devices I have looked at on Amazon
2. If you opt for connecting to the B2 via optical (spdif) then you cannot use the Web UI to control volume. That output bypasses the B2amplifier.
You will need to convert to analog at some point using a DAC either before transmission over Bluetooth or at the receiving end. (someone please correct me if that's not the case)
John