The anti theft ligth is flashing and it wont let me start the car i have a key but it does nothing

The security system has armed itself and needs to be disarmed.... unfortunately, this vehicle has the FORD PATS key based engine disabling system, and it's not recognizing the chip in your
key...if you have another key, try it. You can also try locking and unlocking the doors with the key to disarm. Disconnect negative terminal on the battery for at least 30 minutes, sometimes this will let the capicators drain and it will start. Other than that u'll need a reprogram to get it back to normal. Good luck---I hope this helps.

U need to look in ur manual it will give u the step by step sequencing on how to reset it