In TaxSlayer Pro, preparing and filing Form 990-N starts with beginning either Form 990 or 990-EZ, then after entering the heading information selecting to file Form 990-N instead. See here for more information about creating and e-filing form 990-N.
Once Form 990-N has been selected, the remainder of the return outside of the heading information is ignored, since the return is not being filed as Form 990 or 990-EZ. Additionally, the IRS has dubbed Form 990-N an "Electronic Notice" or "e-Postcard" since it only exists in digital form. Thus, there is no return available to print since no return has been prepared.
If you're filing Form 990-N, you can enter additional information beyond the heading information if you wish, but Form 990 or 990-EZ, whichever you used to begin the return, is not available for printing since, strictly speaking, it wasn't prepared and filed with the IRS.
Additional Information:
Form 990-N - Annual Electronic Notice for Small Organizations
Creating a Basic Form 990 - Return of Organization Exempt From Income Tax
Creating a Basic Form 990-EZ - Short Form Return of Organization Exempt From Income Tax