How to know if a project is a subproject with the API

Hi

In the previous version, we were using the API "/projeqtor/api?uri=project/all" and among the information it gots, we were being able to get the parent of a project (I think) and with that, we were able to know if the project was sub-project from another one. Now that field is not in the response of that API anymore.
Do you know how we can do to know if a project is a subproject from another, in version 11.0.2?

Thanks!
Luis