Question about Logitech G Pro X 2 Lightspeed

Your question is a little unclear. Your question is a little unclear. Are you talking through the whole headset or just the microphone? The entire headset connects to your computer via Bluetooth, Lightning connector(dongle) or cable. If you are speaking through the microphone only: The microphone only works when it is connected to the headset. As soon as you remove it from the headset, it does not work.

Yes, the micropone can be used via all three connection options (BT, Lightspeed dongle and cable).