How do I configure access over ssh for an authenticated Rsync Server Module?

The docs explain state " If you want to protect the modules you can select the next tab and choose a server username and establish a password. Be aware the password is only for the modules, is not the linux password.".

Knowing this, how do I then allow ssh access? It would seem the username and password created within the module configuration doesn't have ssh access since it is not a linux account and can't have the _ssh group.

Currently I am trying to get an rsync task from my Synology NAS to use ssh for transport encryption (ideally using keys instead of a password), but I don't how to set that up, since I'm unsure what account to ssh into in order to perform the rsync task.

This current setup works (where rsync is the user I created in the rsync settings, not a linux user in OMV).

Enabling transfer encryption understandably gives a failed to connect error, since "rsync" isn't an actual user that I can connect to ssh with.

What should I do here? I could generate an ssh key pair for the HyperBackup user but I'm not sure what user to copy ssh public keys to on the OMV system.

Thanks for the help!

Sorry for the confusion, the server module is on OpenMediaVault. Synology just connects to that rsync server. I have the same issue when connecting 2 OMV servers as well, since when creating a new task with public key authentication, there is no option to also provide a rsync daemon password (which causes an issue when "Authenticate users" is enabled on the server module).

That's what I currently have set up and it works great. I have a module in OMV that requires username and password access but I can't access it over ssh.
If I'm using an ssh certificate, do I add the client's public key to the root folder or is there another user that OpenMediaVault uses for rsync server operations?

I think this came from my misunderstanding in how rsync works. If I understand correctly, rsync traffic is never and can't be encrypted. Rsync over ssh isn't truly connecting an rsync client to module but rather an rsync client obfuscation that logs in and transfers files purely over ssh, no rsync server on the remote required. That would mean you can either have an rsync server to connect to with an rsync password, or you can connect to the remote directly over ssh with a public key authentication, not both.

On synology, only admin users can use ssh (stupid rule, i know), so I'm just going to use a standard rsync module.