Redirect to external URL is slow

I am creating application using angular, in my app, i am redirecting to external url with post some data, but during redirection url is changes in the browser tab but it shows the previous page for some seconds. Below is the code:

          const myform = document.createElement('form');
          const mapInput = document.createElement('input');
          myform.method = 'POST';
          myform.action = url;
          myform.style.display = 'none';
          mapInput.name = 'token';
          mapInput.value = tokedata;
          myform.appendChild(mapInput);
          document.body.appendChild(myform);
          myform.submit();

I need quick redirection to external url