Please notice that Qlik Sense Desktop is an evaluation product. It offer full functionality without a license fee, so that you can evaluate the capabilities of Qlik Sense. The Qlik Sense Desktop will expire when the next feature releases is available, meaning that you have to upgrade it on regular interval. It is not a supported scenario to run Qlik Sense Desktop as a service.
For proof of concept or expanding testing of the product, the recommendation is that you get in touch with Qlik sales representatives in order to get a proper evaluation license. This will enable you to try Qlik Sense Enterprise as a proper server service. Please contact Qlik Qoncierge for more details on how to get in contact with your local sales team.