It’s possible to optimize the usage of Microsoft Graph Api by batching requests. There is a limitation for 20 requests in one batch request.

Here is a simplified examle:

The connection to Microsoft Graph with Flask-OAuthlib described well in this tutorial.

One detail it’s missing - how to refresh the access token, because it expires in an hour. In Flask-OAuthlib there is no method for this but it can be done easily with a POST request.