Thank you for your answer. Unfortunately, I have too little experience to make a change myself and recompile the system. It is the module in the attached photo. Then I will probably buy a USB Bluetooth adapter. Thanks again for your help.
Is there now a build for the Pine64 with the “PINE A64 WIFI 802.11BGN/BLUETOOTH 4.0 MODULE” attached? I have seen that this discussion has been held before but without a result. The option is apparently not activated in the DeviceTree. Is it possible to build a suitable version yourself with reasonable effort?