How do I perform an onside kick from a regular kick formation in Madden 17?

I learned today that Madden included surprise onside kicks a few years ago yet I have never seen one until today during an online match. I was receiving the kick, and the kicking team's players were lined up regularly. Then, the kicker reset closer to the ball, and performed an onside kick from the regular formation. How is this done, and why in the world is this not documented in the manual or the training drills??? Additionally, what else is 'hidden' in this game?