How to implement gspay payment gateway in html ?

HTML Code:

<!--GSPay gateway-->  

<form target=_new method=post

      action="https://secure.redirect2pay.com/payment/pay.php">

    <input type=hidden name="siteID" value="xxxxx"> // replace xxxxx to your siteId on GSPay

    <input type=hidden name='OrderDescription[1]' value='PC Tuneup Software'>

    <input type=hidden name='Amount[1]' value='10'>

    <input type=hidden name='Qty[1]' value='1'>

    <input type="hidden" name="OrderID" value="25Nov2008152022_25" />

    <input type="hidden" name="customerFullName" value="Md Boktiar Rahaman" />

    <input type="hidden" name="customerEmail" value="boktiar2012@gmail.com" />

        <input type="hidden" name="returnURL" value="http://www.example.com/return.aspx" />

        <input type="hidden" name="ApproveURL" value="http://www.example.com/return_approved.aspx" />

        <input type="hidden" name="DeclineURL" value="http://www.example.com/return_declined.aspx" />

    <input type=submit value="Checkout">

        

</form>

<!--/GSPay gateway-->

UI: