Where is WPS button on airport and if it does not exist, how do I follow instructions from Netgear Extender

What operating system are you using on the computer that is configuring the AirPort router?

You don't have to add a printer to use the WPS setup in AirPort Utility. Any WPS device will work.

Instead of a "button", Apple uses a "first attempt" method, but it is the same as if you were pressing a button....and it is a lot more secure than a physical button that anyone could press and create problems.