That keyhole turns 1/4 turn in either direction, to reset your alarm and/or shut it off.
P.S. Lots of owners THINK they did not receive an owners manual....some DEALERS do not know any better.
Tilt your drivers seat forward. Locate a large sewn-on pocket on the seatback. Reach very deeply into this pocket and find a small bundle. THERE you have it! Some folks found it on the 2nd look, after INSISTING it was not there the first look.
Dig Deep!