About communications for Restore to Amazon EC2 Helper Appliance

[netwichi]

When performing a Restore to Amazon EC2 from VBR,
TCP22/443 is listed from the Backup Server or Backup Repository to the Helper Appliance.
If the Backup Repository is S3, does the Helper Appliance communicate via TCP443 from the Gateway Server?
Or does the Helper Appliance communicate directly with S3?
https://helpcenter.veeam.com/docs/backu ... _to_amazon