I noticed some errors in the documentation. The reply URL isn't pointing to the new Reactive CallBack but to the Web Traditional.
It's also missing the needed rights in Azure AD for API Access. Correct access needs to be;
So as to not leave readers in suspense, the correct callback is "https://<YourOutsystemsServer>/MSLoginConnectorReactive/CallbackPage"
Zachary thanks for your note. I've added a note the documentation and will update screenshots when get a moment.