Scrapinghub and Portia knowledgeable person needed to fix problem

We need someone to show us how to get Portia the program in Scrapinghub to paginate. That means how can we get the program to scrape only the pages with these items- see link for example: this is the overview of the category page----- [login to view URL] this is an example of the details page for the first item on the category page----- [login to view URL] So the problem is when we try to scrape a detail page how can we make the Portia program go to the next page/product in the category we have selected. We think it has to do with the circled spot on the attached screen capture. If you know how to make the scrape paginate to where we want it to please explain it to us or be able to provide good visual aids to explain it to us.