Grant permissions to the application in Azure

1. In the Azure Management Portal, select the Active Directory tab and an Office 365 tenant.
2. Select the Applications tab and click the application that you want to configure.
3. In the permissions to other applications section, add the Microsoft Graph application.
4. For the Microsoft Graph application add the following application permissions:
   • Read and write calendars in all mailboxes
   • Ready directory data
5. Save the changes.