Juspay web authentication

gistfile1.js

var juspayResponse = JSON.parse(res); // assuming that `res` holds the data return by JusPay API
var url = juspayResponse.payment.authentication.url
var method = juspayResponse.payment.authentication.method

var frm = document.createElement("form")
frm.style.display = "none"; // ensure that the form is hidden from the user
frm.setAttribute("method", method);
frm.setAttribute("action", url);

if(method === "POST") {
  var params = juspayResponse.payment.authentication.params
  for(var key in params) {
    var value = params[key];
    var field = document.createElement("input");
    field.setAttribute("type", "hidden");
    field.setAttribute("name", key);
    field.setAttribute("value", value);
    frm.appendChild(field);
  }
}

document.body.appendChild(frm)
// form is now ready
frm.submit();