You receive this error message:
Cannot connect to the Office Graph. Operations on Office 365 group members and owners will not be executed. Ensure the application was consented by a global administrator and try again.
This error can happen if you do not have sufficient rights to delegate the required permissions to the application.
This is due to limitations in the Microsoft Graph API, which is needed to add/remove Office 365 Group members and query group information.
The permissions needed in the Graph API require a Global Administrator to give their consent to Sharegate. This means that you must be Global Administrator of their tenant in order to run these Group operations during the migration.
Sharegate uses another Microsoft API in order to actually create the Office 365 Group, so this action will still be executed even if the user is not a Global Administrator. So the only actions that won’t be executed are the adding of the Members and Owners to the Office 365 Group.
You can use a Global Administrator account, or your can get a Global Administrator to grant consent of the Azure ShareGate Desktop app to all users.