I have a 95 lincoln towncar and my anti-theft is armed and I can't start my car. on 1995 Lincoln Town Car

I had a new driver's door installed and when I try to start the car, it clicks and the anti-theft light blinks fast. I don't know what else to do. Any advice pleae is welcomed.

Asked by for the 1995 Lincoln Town Car
try getting codes with scanner then post codes