To send digital ink from the Live PDF iOS app, you must first "pair" your Live Pen 2 to the iOS device running the app.
Note: Currently, only Live Pen 2 digital pens may be paired to iOS devices.
Here are the two ways to pair your Live Pen 2:
(Recommended) Pairing via pairing pidget - This will work for anyone, but is especially useful if you use Live PDF with your mobile device only.
(Alternative) Pairing via Anoto penDirector - This may be used with Anoto penDirector installed on a PC.