If you are saying you want to add a schedule K-1 to the state only, you cannot do this. Because many state taxes follow federal taxes, the state software is not independent of the federal software.
All tax forms must be reported on the federal level and will then transfer to the state, when you start it (even if you aren't filing the federal return and are only filing ND).
If you need to add a schedule K-1 to federal, you'll need to delete your state and re-transfer it, once you have everything entered. To do so (I'm presuming you are in desktop software for windows, if not please comment below): click File in the top left, then select Remove a state return.
To add your schedule K-1: click the Income tab >> select I'll choose what I work on to get to the full listing >> scroll down to Business Investment and Estate/Trust Income >> click Edit/Update next to Schedule K-1 >> click add a schedule K-1
Let me know how it goes or if you have questions.