You need to use Global Admin account for login When configuring the connection to the Exchange server, the connection process verifies if the provided admin account is assigned either the User management administrator or Global administrator role.
Note: Only the credentials specified in the Admin account step are used to connect to the source or target server. Credentials provided in the Configuration step are only used once to assign the missing roles. Therefore, you will not be asked to provide the credentials of other admin users again as long as you use the same admin account for the migration process.
Must set impersonation rights to the Global Admin account Application Impersonation is a management role that enables applications to impersonate users to perform actions on their behalf using EWS. The role can be granted only to one user on the account. Click here to set impersonation rights to the Global Admin account