Hi @Shivam Sood ,
Thank you for reaching out to us. As I see you are getting error 401 while performing GET /v1.0/users/{user-id}/calendars to Graph API.
Error 401 is an Unauthorized error. Make sure that your application is presenting a valid access token to Microsoft Graph as part of the request. This error often means that the access token may be missing in the HTTP authenticate request header or that the token is invalid or has expired.
We strongly recommend that you use the Microsoft Authentication Library (MSAL) for access token acquisition.
Also, you can check your scopes by decoding access token in https://jwt.ms/, make sure you have Calendars.Read, Calendars.ReadWrite permission added. Please refer the link for more details.
For application permission token, the permissions are in the “roles” claim:
For delegated permission token, the permissions are in the “scp” claim.
Hope this helps.
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