Pair your cameras by pressing the small white button on the back of the main camera unit, the red lights will flash to show that it is in pairing mode. 


On the screen of the recorder, hover over one of the camera channels and press the sideways camera icon in the middle at the top. 


This will pair the camera to that channel on the recorder.


Repeat for any other cameras – each NVR will support up to 6 cameras.