1. Create a sign-up form
  2.  Embed Form in Your Wordpress Site. If adding the code inside the page won't work, try adding it in a widget first then add the widget to your page.
  3. If you need to add custom field, here's how.
  4. Finally, the default action after form submission is just it displays a Success message. If you want to redirect it to a thank you page, just add the following code after "<!-- The following code must be included to ensure your sign-up form works properly. -->"    Just change the Thank you URL.   


         <input data-id="url:input" type="hidden" name="url" value="http://domain.com/thank-you">