I know there are many similar questions, but none of the solutions work for me.

My problem is that with the [Live Composer Plugin][1] the [`url_to_postid()`][2] function does not return a post id for Live Composer's custom post types, e. g. "Partners", "Project", "Staff". The URL of the permalink for a project named "Testproject" by default has the form `http://localhost/wordpress/?dslc_projects=testproject`. This does not get resolved by `url_to_postid()` into a valid post ID.

The workaround is to set the permalink structure to something other than the default "plain" setting. Then `url_to_postid()` in fact does correctly resolve even LC's custom post types.

However I do not trust the user to remember this workaround. Heck, I don't even trust myself. Hence, I'd like to know, if there is a way to resolve the type of URL above.

I'm new to WordPress, therefore I have not yet messed around with the database directly, have not implemented custom taxonomies and have not provided custom rewrite rules. I don't even know, what the type of URL like `http://localhost/wordpress/?dslc_projects=testproject` is called, although it seems to me to provoke a query in the database to match the `dslc_projects` attribute to `testproject`.  
I'd love to know if this type of URL has a name, so I can google it and learn about it. Also, if someone knows how to get the post ID using those URLs that would be even awesomer. :)


  [1]: https://wordpress.org/plugins/live-composer-page-builder/
  [2]: https://developer.wordpress.org/reference/functions/url_to_postid/