I think this page should help:
Disabling Standard Mode In Qlik Sense - QVSource: The QlikView & Qlik Sense API Connector (Docs)
Unfortunately Qlik have introduced a change in Qlik Sense (relative to QlikView) means you have to edit a setting in Qlik Sense to allow you to be able to use arbitrary load URLs in the load scripts.
Suggest that this change is due to restricting unwanted file system access so we cannot fully appreciate the reasons for it breaking this loading from HTTP behaviour - this is a common requirement in QlikView and Qlik Sense (it's nothing QVSource specific).
We are trying to persuade Qlik to improve this situation.
See this thread for some more info and comments:
Load Web File dynamically