My key broke I have an extra but it's not programmed - 2006 Pontiac G6?

My key broke and when I bought my car the dealer gave me an extra key it goes into the car and everything but it wot turn it on cause it's not programmed what can i do? I went to the dealer they said to put it into acc mode and it would program itself but it didn't work I dont wanna pay to tow it to the dealer :/