page is not loaded on iOS 8.1 using web view

I'm woking on an app which will load a web view. But the issue is iOS 9.x is working good but iOS 9.3.1 and iOS 8.x is not loading the web view page.

Below is my code :

let html = "<script type='text/javascript'> function paymentCall() { document.M2UPayment.target='M2UPayment'; window.open('about:blank', 'M2UPayment', 'width=400,height=350'); document.M2UPayment.submit(); } </script> <form action='\(url)' method='post' target='M2UPayment' name='M2UPayment'> <input type = 'hidden' name='q' value='\(MString)'> <input type = 'hidden' name='i' value='DPE'><center><b>PAY NOW WITH MAYBANK</b><br><br>Please do not Reload, Refresh or click on the back button for this page!<br><br><b>MEMBER ID : \(memberid)<br>TRANSACTION ID : \(TransId)<br>AMOUNT : \(amount)<br></b><br><br><input type ='button' onclick='paymentCall()' value = 'Pay Now' style='-webkit-appearance: none;background-color :#face00; border-color : #face00; color : black; width : 95%; height : 35px;'></center><br><br></form>"
    print("HTML : \(html)")


    webView.loadHTMLString(html, baseURL: nil)



}

Please advise me as I'm really blur. The above will give the below code for html :

<script type='text/javascript'> function paymentCall() { document.M2UPayment.target='M2UPayment'; window.open('about:blank', 'M2UPayment', 'width=400,height=350'); document.M2UPayment.submit(); } </script> <form action='http://ift.tt/1NoTyyf?' method='post' target='M2UPayment' name='M2UPayment'> <input type = 'hidden' name='q' value='uGJ6%2Bl4prlW5E%2BdLg%2FOaS%2BNAyl0xTJmTiSTUFbeyIUjjErW3eCZ7lSRB3dpQULlUl3YRbfCVHn%2Bem%2FDZowvTdnAVKv4oEy1V%2FSMkxRGyIaENFJx0mx0hV5op%2F2aaRy59YMMjHwERIhuAIgqdeNF5SyKRpqQMLDhkUCpOsfz%2BKi0VhxcbjaZgOcoInZaDzXp6z4Dvtor%2FpvC5ZVZY0zQwrfrEasdufsfvVcGHjsI9dVeaY7bIO5JM54PcRAAUH0WK'> <input type = 'hidden' name='i' value='DPE'><center><b>PAY NOW WITH MAYBANK</b><br><br>Please do not Reload, Refresh or click on the back button for this page!<br><br><b>MEMBER ID : T000015<br>TRANSACTION ID : 7I4RDCB3YTK6WPSa<br>AMOUNT : RM 2500<br></b><br><br><input type ='submit' onclick='paymentCall()' value = 'Pay Now' style='-webkit-appearance: none;background-color :#face00; border-color : #face00; color : black; width : 95%; height : 35px;'></center><br><br></form>