Question about LogiLink Bluetooth Adapter

Hello I have installed the Bluetooth dongle and loaded the SW from the mini CD according to the instructions. Despite many attempts and activating the Bluetooth dongle in WIN10, Fitbit cannot recognise Bluetooth. According to the device information in WIN10, the thing works without problems. How do I get the CHARGE2 from Fitbit to connect to this interface? FITBIT claims not to recognise Bluetooth. . . . Helpful tips are very welcome!