Stephen Ball

If anyone is looking at this again. I would agree that its a complex API to get working. Mainly due to permissions.

This is a useful tool - https://developer.microsoft.com/en-us/graph/graph-explorer

You can log in as a user and run multiple API calls to see examples of how they work and if they work. This takes some of the guessing away from "did I set it up right".

The Overview of the Microsoft Graph https://docs.microsoft.com/en-us/graph/overview is also pretty good. 

As @David Millington mentioned, we have been working with the R&D team to share tips learned to help speed up VCL applications under remote desktop - to read about it, including a code sample see:

https://blogs.embarcadero.com/how-to-speed-up-remote-desktop-applications/