To import products under Products > Products we suggest to set up one manually so you have a point of reference and click”Export All Products”. PrintNow locks the spreadsheet to prevent mistakes but you could simply copy and paste our version into a new spreadsheet of your own. The sheet name is important for both categories and products so use our version or make sure to follow it in that regard as well as the order of the columns. Under Products > Categories the rules are the same. Import new or replace content.