Here is a general method to find input for something on a return. 

Check Return > Forms > All > Click US or the State > Find the form (use search) > look for boxes or lines shaded in blue. Click the blue shaded area for what you want. 

In this case I would click page 2 of 172 where it says 1st preceding tax year ended. 

I hope this gets you there. If not, give some numbers and years you are trying to get work. If a current year NOL, it should be automatic.