New Prius C owner with key fob issue

We just scored a great one owner 2013 Prius C 4, with only 2600 miles on her. We just love this Little gem of a car. It came with 2 sets of keys, actual keys on the fobs, not just fobs. So one key is programed to lock the doors, but the other one does not. I have found 3 different ways to get into the programing mode from the internet, and none of them get me into the key programing mode. Please help? Thanks.....................Old Iron

 

I got it figured out. I went back to the basics, and put a new battery in the fob. Now both key lock the doors.