It depends on what you're trying to accomplish by registering the dog. You do you have an American Pit Bull Terrier or an American Bully? If you have an APBT
there are other registries you can do like ADBA for conformation and Weight Pull, you can also do Bona Fide Kennel Club for recording purposes, and AADR for conformation and WP. There might be others but I am tired and cannot think of anymore.
If you have an American Bully then you should register them with the ABKC and then trash your UKC paperwork since you should only have registration with the kennel club that represents your breed.