test.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Form test</title>
    <style media="screen">
      input {
        display: block;
        margin-bottom: 10px;
      }
    </style>
  </head>
  <body>
    <!-- <form action="http://localhost:3000/sign/26a49c65-70ce-48d7-9932-202b874c9912" method="POST"> -->

    <!-- dev -->
    <form action="https://6bzimew51k.execute-api.us-east-1.amazonaws.com/prod/sign/26a49c65-70ce-48d7-9932-202b874c9912" method="POST">

    <!-- prod -->
    <!-- <form action="https://a0irep8fl7.execute-api.us-east-1.amazonaws.com/prod/sign/26a49c65-70ce-48d7-9932-202b874c9912" method="POST"> -->

      <label for="name">Name</label>
      <input type="text" name="name"></input>
      <label for="email">Email</label>
      <input type="text" name="email"></input>
      <label for="zipCode">Zip code</label>
      <input type="text" name="zipCode"></input>
      <button type="submit">Sign form</button>
    </form>
  </body>
</html>