I am using Paytm CheckOut JS in dart webview with redirect as false in merchant config.

===JS Code===
"merchant": {
    "redirect": false
},
"handler": {
   "notifyMerchant": function(eventName,data){
        console.log("notifyMerchant handler function called");
        console.log("eventName => ",eventName);
        console.log("data => ",data);
    },
   transactionStatus: function(data){
        console.log("payment status ", data);  
        var form = document.createElement('form');
        document.body.appendChild(form);
        form.method = 'post';
        form.action = 'https://<myWebsite>/paymentReceipt.php';
        for (var name in data) {
            var input = document.createElement('input');
            input.type = 'hidden';
            input.name = name;
            input.value = data[name];
            form.appendChild(input);
        }
         form.submit();
    },
  
}

===Code ENDS===

I wanted to redirect the transaction Status response to my page paymentReceipt.php to process it. The redirect happens properly in desktop browser. But when it is run on a flutter app through a webview the transaction is sucessfull but does not redirect to my page paymentReceipt.php instead it redirects to the a paytm page.