OK, but really can't know what the issue is there. "Online" is more difficult to troubleshoot.
Get into the NC section of the interview.
Find the "Other Situations" section and go into it there (in the NC interview, not the Federal)
Select the "File an Extension" section and go in there.
If you used that section to prepare/file your NC extension, it may already be filled out. Just make sure that the extension payment you actually made at that time is properly filled in, with the exact $$ amount you paid.
If it's already there, then it should already be reflected in your NC tax return on line 21b of the NC form D-400.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
