Permissions are migrated as the final step in a transfer. As an administrator, you can additionally choose to divert migrating permissions until the data transfer process has finished.
Migrate permissions as part of the full migration
When permissions are enabled, launching a Full Migration will result in permissions being migrated as the final step in the process.
Migrate permissions ad-hoc
To trigger migrating of permissions manually at any stage, you can choose Start Delta and Permission Migration.