While the official way of remote syncing a computer with the My Cloud requires the use of the WD Sync program, there are various unofficial workarounds to the issue ranging from using the WebDAVMod to remote map the My Cloud, to setting up a VPN tunnel, to using the insecure FTP (or some form of secure FTP), when using third party sync programs. Each method has its own potential issues.
https://community.wd.com/t/app-clouddavmod-v1-0-for-firmware-v4-05-2016/161543
