In order to send reports to Hub you need to create a Publish task. You will find the option to create a publish task under Tasks>Publish Task in the NPrinting Admin console. Once you create a Publish Task, edit the settings and go to Destinations. Under Destinations you should see an option for Hub.
Set a schedule or do a run now and once it triggers this should be delivered to your Hub. On the hub you will find it under your Work area on the left.