InAppBrowser excutescript() method is not returning innerHtml code? - ionic2

Question

I was integrating the payU payment API in my Ionic app. I was able to get the payment success url of payU but the InAppBrowser excuteScript() method is not returning the innerHtml of the payment success url .
Please provide an relevant solution .
Please find my code below.
onDeviceReadyTest(url) {
console.log('url passed'+ url);
//let browser = new InAppBrowser(url,'_blank');
const browser = this.iab.create(url,'_blank');
browser.on('loadstart').subscribe(
(res) => {
// Handle url checking and body parsing here
console.log('event start with ' + res.url);
},
(error) => {
// Handle error here
console.log(error);
}
);
browser.on('loadstop').subscribe(
(res) => {
// Handle url checking and body parsing here
console.log('event stop with ' + res.url);
if(res.url.match("https://payu.herokuapp.com/success")) {
console.log('event match with ' + res.url);
//alert( browser.innerHTML);
browser.executeScript({code:"document.body.innerText"}),
function(values){
alert( values[ 0 ] );
var a = this.getValue(values[0], 'mihpayid');
var b = this.getValue(values[0], 'status');
var c = this.getValue(values[0], 'unmappedstatus');
console.log(a + b + c);//you can capture values from return
}
}
},
(error) => {
// Handle error here
console.log(error);
}
);
this.iabRef.addEventListener('loadstart', this.iabLoadStart);
this.iabRef.addEventListener('loadstop', this.iabLoadStop);
this.iabRef.addEventListener('loaderror', this.iabLoadError);
this.iabRef.addEventListener('exit', this.iabClose);
}`