@ADM-BEdwards , thank you for posting question on Microsoft Q&A.
I understand that you are trying to access Microsoft Graph API using JSON API from Infinity Datasource The documentation for Infinity contains detailed steps for authentication against Azure APIs - Azure Authentication
You may also refer to Auth basics for Graph API here - Authentication and authorization basics.
Regarding your feedback for Graph API datasource, please post this idea on the following link for it to be considered by Azure Managed Grafana Product group - Azure Managed Grafana Feedback
Hope this helps.