pretty urls on custom pages

Hi,

I am working with a prepaid theme that has custom pages where an interface allows the user to click through various subcategories within a parent category. The issue is that the url’s end with a category id number rather than a category name. The permalink setting don’t seem to affect this and I’m wondering if anyone might have an idea on how I could go about serving up prettier url’s for these pages. Here’s an example:

https://www.brookscustom.com/site-2016/portfolio/#category_id_43

If anyone has ideas about a starting point for this it would be greatly appreciated. Thanks.