To access SharePoint through the Graph API, you need to register the application in Azure, and properties such as the client id will be automatically generated. You can refer to the registration process in this document.
In addition, I share two related API endpoints for managing SharePoint:
Manage Excel through the Graph API:
https://learn.microsoft.com/en-us/graph/api/resources/excel?view=graph-rest-1.0
Manage files stored in SharePoint through the Graph API:
https://learn.microsoft.com/en-us/graph/api/resources/onedrive?view=graph-rest-1.0
Finally, you can also call the Graph API directly through the Graph Explorer without registering the app. See the documentation for more details.
Hope this helps.
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