Maybe I'm doing something wrong still.
In my CPT called Impact Stories, under the Post Relationship section, for "Children" I checked the "Page" box. Is that correct?
Next I open one of the Impact Story posts, I see the Fields Table, but no dropdown menu to select the built-in WordPress page called "Impact" that I created. I want the Impact Story posts to be children of the Impact page. You say that it's possible to create parent/child relationships among Types CPTs and built-in WordPress posts and pages, but I can't figure it out…
The URL structure I'm trying to achieve is this:
domain.com/impact/impact-story/title-of-story <- singular
domain.com/impact/impact-stories/ <- archive
Again, the Impact page is a built-in wordpress page. How do I assign it as the parent of all Impact Story posts?
I'm attaching a screen grab of the Fields Table.
Thanks for you patience.