Since your vehicle is not onboard programmable or you need key cutting, you will need a dealer or automotive locksmith to program the vehicle to accept the replacement remote or key or to cut a key. Please use an automotive locksmith rather than the dealer. You are likely to get a better service for a more reasonable price. Locksmiths make their prices based on their local market as well as the cost of the equipment used for you cutting or programming.
Remote For GMC:
Factory Smart Key Remote with FCC ID M3N-32337100. The GMC part number is 84209236. This remote has 5 buttons and sends it's signals on a frequency of 433 MHz. Remote is tested and guaranteed to work. An automotive locksmith will program your new remotes or keys by hooking up an expensive scan tool to your vehicle?? computer and making the vehicle learn the new remotes or keys.
The following vehicles can use this remote when equipped with the factory keyless entry system:
GMC Sierra (2019-2020).