Unix & SSH: Recieve "Skipped Duo login for 'my account':

Hello,

I’ve installed login_duo on my test Ubuntu 16.x box.
Installed with no issues.

When I go to test as a regular local user, by manually running /usr/sbin/login_duo on the CLI, I get the following - 4] Skipped Duo login for ‘my account’: Allowing unknown user -

Not sure exactly how to resolve.
Any advice would be much appreciated.

Frank