I am trying to get all posts from category `products`. My template looks like this: `/products/PARENT_CATEGORY/CHILD_CATEGORY`. What I need is all the posts from every CHILD\_CATEGORY.

I try to access it via `/posts?categories=28`, but it returns no posts, as the category with ID of 28 doesn't have any posts itself. But its child, for example, category with ID of 40, has some posts. Should I access them like `/posts?categories=40,41,42...`? Or there is another way to do it?