QlikSense Web Integration - Windows Authentication

[Anonymous]

Trying to embed Qlik Sense visuals in a website, both on the same server (IIS and Qlik Sense). My JavaScript file has a code to open an App and access an object :

var app = qlik.openApp('13892ddf-79b8-480f-aa07-3556683f4ed3', config);

app.getObject(document.getElementById('TopCust'), 'XWxKDzh');

because of this code, I see errors in this order:
"listener must be a function"

The page refreshes and same error message shows 2-3 times and then gets redirected to this:
"Windows authentication (or Service Unavailable)"

In Qlik Sense QMC, this is how the Virtual Proxy is set up:

Any ideas on resolving this ?