In case anyone else encountered this problem. You have to edit your function and check the "has return value" box. Then your return will work. After this you have to use "Call Function" again and now you have a new field for saving results.
@rere003 You need to start loop for element which repeats on page. For example, if you start loop on >CSS> div, you will iterate all divs, also you can use >CSS> a as loop to iterate all links.
Regarding this site, every product has product-list-wrapper class, so you can iterate over >CSS> .product-list-wrapper
