What are my options for having a spare key made

Since the dealership I bought it from wasn’t a Chevy dealership I am not sure they could have done it.

Will be interested to hear what you find out after you consult with a locksmith and/or your local hardware store. Please report back on how it goes!

Quoting lion9car

“If this were me, I wouldn’t have bought the car unless the dealership provided the second key”.
They certainly aren’t required to, but if you demand it be part of your deal, they might go for it.

The deal is whatever you can make it. When I got my car, the Nav disc was missing. The dealer reimbursed me for a disc I bought on ebay. I’m sure if it would have occurred to me to press for a 2nd key, I would have gotten it, but I didn’t realize there was only one until it was a done deal. As it was, the small-lot dealer did actually call the prior owner (who traded it in) and tried to locate a 2nd key (I was there when he called), though stopped short of providing one when it was not found.