First pair your computer with the Bluetooth module. Open Bluetooth-Add a device. You should see a device that is named Firefly-xxxx. The pairing code is 1234. Pair the computer wih Firefly.

It is recommended that the Bluetooth module be external, utilizing a serial comm port, as the software communicates via serial communication. If your Bluetooth is connected and paired, you need to determine what comm port Windows is utilizing. This is determined by opening Bluetooth settings (click on Bluetooth icon). Click the Firefly icon and open the Services tab. This will show Bluetooth Services with the com listed.

For more complete instructions see  http://ww1.microchip.com/downloads/en/DeviceDoc/rn-4142-ek-ug-1.0.pdf paragraph 4.6 "Making a Bluetooth Connection"