Turn your switchbox on, then go into the main iPad/Android settings, go to bluetooth settings and turn bluetooth on. The switchbox should appear in the list of available devices. Tap on in once and it should pair up automatically.
If this doesn’t work it’s possible that the switchbox is already paired with another device which means it needs to be reset. Press and hold the power button for around 8 seconds (until the LED starts flashing very quickly between red & green). Then return to your iPad or Android settings, turn bluetooth off, wait 10 seconds, then repeat the process.