Don't have a momentary switch, what else can I use?
It should work.  They have 4 pins for structural strength, since they are meant to be soldered on a pcb.  It has two pairs of pins, where each pin in a pair is electrically connected to the other, as illustrated in the following diagram (taken from google images):



As you can see, pins 1 &amp; 2 are connected, and so are 3 &amp; 4.

If it is normally closed instead of normally open, you can still make it work as expected by tweaking the software (may be as simple as inverting the logic).