ELEGIANT BTI-066 2-in-1 Bluetooth 5.0 Transmitter Receiver, Dual-link Support, a: "1. Turn on the Bluetooth headphones and make it in pairing state. 2. Switch the BTI-066 to TX mode and turn it on, it would auto search and pair with your headphones. 3. Plug the BTI-066 into the TV audio output jack and make the right setting."