Calling external js through jslib

I have followed this: Unity - Manual: Interaction with browser scripting
to create a C# script that calls a jslib function, which successfully runs something like: window.alert(“Hello, world!”);
Now i want it to run a function from the index file in the template. How do i call that?
I have dismissed Application.ExternalCall() as it is marked obsolete.

I hope it might be useful

![alt text] [1]
Index.html


.jslib file and class in Unity