Gotta find out what's in there fisrt. Could be pre-programmed bypass or key in box.
When you got it installed, did they say anthing about you losing or having to get a spare key??
Try to look under your dash for a small box. There will be a couple. Look for the one with the least amount of wires coming out of it. Grab the part number from it. Do you now what alarm system is in there?? It might help.