Acronis and My Cloud Home Duo

I am trying to set up Acronis True Image 2019 to back up my entire compter to my WD Home Duo.
I get as far as the enter Authentication Settings screen.
I’ve tried every combination of User Name and Password without success.
What are the User Name and Password? Where can I find them?


@Peter_Spring The My Cloud Home Duo //MyCloud-xxxxx/Public samba share is not password protected, but Windows 10 disables SMBv2 guest access by defualt now.