Proccess

Call Generate Url api with valid parameter define above. and In Response, in success case Encryption Data and Url will received .
You have to auto redirect POST form to response url with Encryption Data field having response value

<form method="post" action="URL received from generate url API">
  <textarea name="Encryption_Data" style="display:none">value received from generate url API</textarea>
  <input type="submit" value="Submit">
</form>