I thought I would give it a try out with the AX7 by registring the native application on Azure AD.
See wiki and search half way in the page for Register a native application with AAD
Navigate to the Azure AD in the new Portal. Click on App registrations.
Create a Native App and enter a Redirect URI.
Click on the Required permissions and select Microsoft Dynamics ERP. Then select the 3 delegated permissions.
Should look like this at the end.