Undefined value while executing JS function using V8Engine

Question

I am calling Execute method of javascript function from C# using V8ScriptEngine but i got undefined value in C#.What should i change in Javascript function? How to know callback function is called or not? Also please suggest other ways to call api from Javascript using ClearScript(V8ScriptEngine).

 

Javascript Function:

function Execute(paraList){
var finalUrl = "http://172.29.134.69:9006/api/Line/GetStationDefectsByStationId?stationId=1";
var response=get(finalUrl,function(){var resp=this.response;return resp;});
return response;
}
function get(url, callback) {
var xhr = new XMLHttpRequest();
xhr.open("GET",url, true);
xhr.send("");
xhr.onreadystatechange = function () {
if (xhr.readyState == 4) {
if (typeof callback === "function") {
callback.apply(xhr);}
}
};
}

C# Code:calling javascript function from c# using V8ScriptEngine

V8ScriptEngine _v8Engine = new V8ScriptEngine(V8ScriptEngineFlags.EnableDebugging);
_v8Engine.Execute(Script_Text);
_v8Engine.AddCOMType("XMLHttpRequest", "MSXML2.XMLHTTP");
object returnedVal = _v8Engine.Script.Execute();
return returnedVal;