D365FO Odata - d365 postman please verify that the user is valid and set up correctly

 {

    "Message": "Please verify that the user is valid and set up correctly."

}

Sol:

System Administration > Setup > Azure Active Directory Applications

Click the +New button to add a new registration.  

Grab the Application ID from the registration in the Azure Portal and insert it into the Client ID field.

Fill out the rest of the fields as necessary.