You connect to your Microsoft 365 environment and you get the following warning:
You are not authorized to get a valid Azure ShareGate migration application access token. Some limitations might apply.
The Azure application allows the ShareGate migration tool to identify to Microsoft 365 that it is running operations on your tenant through an access token. For more information, see What is the Azure ShareGate migration app?
If you connect with an external user account, the ShareGate migration tool is unable to use an access token. You will be able to use the ShareGate migration tool, but you might experience more throttling, and you will not have the ability to create Microsoft 365 groups.
You can use your current account if you see no problems with the limitations.
To get the most out of the ShareGate migration tool, use a regular AD account to connect in a Microsoft 365 environment that was granted admin consent of the Azure ShareGate migration app to all users.