Did you make sure the chip type of provided key matches the chip type of the existing working key? Did you test the RKE output of the buttons and fobik battery?Did you perform an immobilizer status scan and clear codes before attempting to add the key?
here is a link to an All Keys Lost scenario if it is necessary to erase all keys first. Make sure to get all customer existing keys before erasing all keys.
https://www.youtube.com/watch?v=A_ozjqgA3HQ