Integration to use the Payflow API without using a hosted checkout page

I am facing one issue regarding PayflowLink to work on our iOS Mobile App.

Let me explain the issue. It is happening on iOS mobile app - developed using MeteorJS & ReactJS.

When we click on Pay Now button in our app, the control passes to PayflowLink url ‘’. We can see two options for payment. One is Credit card payment and other is Express Checkout button. When we click on any of these two options, control goes to appropriate page. We can enter our Credit card data but the card details are unable to be accepted and transferred from our app, i,e my screen is auto refreshing.
My code :

<form method="POST" action="" target="_self">
<input type="hidden" name="LOGIN" value="***"/>
<input type="hidden" name="PARTNER" value="***"/>
<input type="hidden" name="DESCRIPTION" value="***"/>
<input type="hidden" name="AMOUNT" value='***'/>
<input type="hidden" name="TYPE" value="S"/>
<input type="hidden" name="RETURNURL" value="***" />
<input type="hidden" name="CANCELURL" value="***" />
<input type="submit" className="btn" value="Pay Now"/>

Any help would be greatly appreciated.