How to list projects which is not under any organization

[Mus]

Hi, 

I am trying to use the API library list_projects to list my projects. But in V3 it seems the parents are no longer optional. I can confirm the same from https://cloud.google.com/resource-manager/reference/rest/v3/projects/list?apix_params=%7B%22parent%2....

Now, can anyone suggest, how to use this API for projects not under any organization structure?