I'm going to guess that you are using Filter Items to get a list of items: https://developers.podio.com/doc/items/filter-items-4496747
As you can see there's a "limit" parameter that will control how many items are returned. How you change that limit parameter in klipfolio I don't know. You'd have to contact klipfolio to find out. We certainly support getting more items from our end.
All the best,