<article class="card card-outline mb-4">
  <div class="card-body">
    <h4 class="card-title">Sign up for our email subscription</h4>
      <form method="POST" action="action_page.php">
        <div class="mb-3">
          <label for="email">Email:</label>
          <input type="email" class="form-control" id="email" placeholder="Enter email" name="email" data-ddg-inputtype="identities.emailAddress" data-ddg-autofill="true" style="background-size: auto 24px !important; background-position: right center !important; background-repeat: no-repeat !important; background-origin: content-box !important; !important; transition: background !important;">
          <div id="emailHelp" class="form-text">We'll never share your email with anyone else.</div>
        </div>
        <button type="submit" class="btn btn-primary">Submit</button>
      </form>
  </div>
</article>
  

Output:

This is a very simple HTML form that gets the user to enter an email address and then it will 'POST' that data to the 'action_page.php' file so that we can use/manipulate the data that the user has provided how we want using PHP.