Yes, if you filed the original 2020 federal and NC returns together, then when you go back into TurboTax to amend the federal return, it should also give you an option to also amend the NC return.
The federal and state taxing authorities generally share information on the numbers filed on the federal and state income tax returns. Since the NC return uses the federal agi of the federal return, you always need to be sure the two tax returns use the same amounts on the return. They must match.
Therefore, you will be required to amend the NC return to match the amended federal return.