When migrating Google Team Drives, you’re hitting the following error :
[FATAL_ERROR] Fatal error during migration process: Google Api Error Google.Apis.Requests.RequestError The attempted action requires shared drive membership.  Errors [ Message[The attempted action requires shared drive membership.] Location[ – ] Reason[teamDriveMembershipRequired] Domain[global]
This is because your migration account must be owner (organizer) of the team drive.
You must add the migration account as organizer of the Google Team Drive.
The platform is also able to add the migration account as organizer of the Team Drive automatically.
To achieve this, you must give the Scope “Drive” to the service account, Drive.ReadOnly will not be sufficient.