Support to apply sensitivity label to a Microsoft 365 group using microsoft graph app permissions

This seems to only be supported using delegated permission according to docs at 

Update group - Microsoft Graph beta | Microsoft Learn

Note: Use of this API to apply sensitivity labels to Microsoft 365 groups is only supported for **delegated permission** scenarios.

Sourced from 

Support to apply sensitivity label to a Microsoft 365 group using app only token · Issue #515 · microsoftgraph/msgraph-beta-sdk-dotnet (github.com)