To call SharePoint specific APIs you need to get a SPO specific access token. You can “swap” an regular MS Graph refresh token for an SPO specific token by doing the following: Get a delegated auth token from graph as you normally would (https://learn.microsoft.com/en-us/graph/auth-v2-user) Use the refresh_token you got and exchange it for an SPO … Read more
Disclaimer: I’m a Microsoft employee. To retrieve and edit calendar events from Outlook.com, both Microsoft Graph API and Outlook REST API endpoints work. If you require Webhooks for an app you are planning to use in production, then you need to use Outlook REST API v2.0 endpoint. Microsoft has Webhooks available in Preview on Microsoft … Read more
You are using the client credential flow here, which means that you cannot dynamically request scopes. You must configure your required permission scopes on your app registration in apps.dev.microsoft.com, then you set the value of scope in your code to https://graph.microsoft.com/.default. See https://developer.microsoft.com/en-us/graph/docs/concepts/auth_v2_service for more details.