I buy a new iPad mini how to register for warranty?

Follow the instructions in the packaging.

When u turn it on follow the set up instructions towards the end u will be given the option to register the iPad.

I followed setup, but never saw the option to register. So how do

I register "after the fact"? I've already loaded my old iPad onto my

new iPad Air 2, but it's not showing in my iTunes devices. What

can I do to get iTunes to recognize it? Thanks.

The past few that I got were registered when I signed into my Apple ID. I never went through and actually "registered" it myself, but when I look on the site under my devices, I can see when it was registered and when the warranty is going to expire on it.

When I go to my iTunes account, only my iPhone is registered, not my new iPad.

How do I "add" it to my "devices"?