If you filed the tax return using TurboTax Desktop.
You just need to click on State Taxes tab and then add a State (NC) or add an other State (NC).
TurboTax Online is close, however, you can get download by click following link.
https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed
After installing software, open your .tax file click on State Taxes tab and then add a State (NC) or add an other State (NC).
I hope this will resolve your issue.
