First, make sure that your headset is turned on. Then, long press the Bluetooth button on the headset (holding it for a second will make it beep by turning the Bluetooth on, but hold it for over 4 seconds for a different beep). If the light is blinking rapidly, that means pairing mode is initiated.
On your Bluetooth-enabled device, make sure "Scan" or similar function is on to see the Arctis Nova headset on the list, then connect them.
Now your headset should output both the audio from the Bluetooth-connected device as well as your PC or other compatible device that uses the Wireless Base Station or the dongle (2.4GHz connection is recommended for gaming).
Bluetooth Controls on SteelSeries Headsets