Take VIN to dealer and get a replacement key that has to be inserted into the ignition and programmed by the car's system in three steps of ten minutes each. A Lock Smith came to my house and my car was programmed in thirty minutes.
I think you can go to a Buick dealership with your VIN code & they can make a new key--call your nearest one & ask them.
I lost the keys to my 1995 BUICK