Now following this step-by-step guide to Setup Pre-requirements for Office 365.
Go to Microsoft Graph >> Application Permissions and add the permissions as per your requirement as shown in Step 8.
Now again click on "Add Permissions" as shown in step#6 and go to "APIs my organization uses" tab and search "Office 365 Exchange Online" and click on it. Then, click on "Application Permissions" and add the permissions as per your requirement as shown in Step 8.
Now add below given permission (and click on Grant admin consent for SysTools) as given below:
If Office 365 is destination platform then you need to add below given permissions:
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