Currently in Qlik NPrinting you are only able to setup one Qlik Sense Hub Destination for your Reports.
Per the knowledge article on Connecting Qlik NPrinting to Multiple Qlik Sense Servers there are the below limitations:
Connect NPrinting Server to Multiple Qlik Sense servers
• You may only publish Qlik NPrinting reports only to a single Qlik Sense Hub. Ie: the QS hub defined in the NPrinting Web Console under 'Destinations\Hub' while logged on as an NPrinting administrator.
• Publishing to multiple Qlik Sense Hubs is not yet supported.
The current feature / enhancement request is to please allow customers to connect multiple Qlik Sense Hub Destinations in Qlik NPrinting.