For subscription box, as shown on demo site:

1. Make sure you have installed ‘MailChimp for WP’ as recommended by the theme.

2. Connect your MailChimp account with the plugin by going to?‘MailChimp for WP’ > ‘MailChimp’ > ‘MailChimp API Settings’. You can get your API key by going to?https://admin.mailchimp.com/account/api?.

3. Now, create form by going to?‘Mailchimp for WP’ > ‘Forms’. Use following code for creating form.

<div class="durja-subscribe-card">
  <div class="card-block">
    <h6 class="title"><i class="fa fa-money"></i> Interested in Discounts?</h6>
    <p class="text-muted">
      <small>Subscribe here and get email when we offer discounts!</small>
    </p>
    <input type="email" name="EMAIL" placeholder="Your email address" required="" class="form-control">
    
    <input type="submit" value="Sign up" class="btn btn-primary">
  </div>
</div>

4. Go to?‘Appearance’ > ‘Widgets’. Add ‘MailChimp Sign-up Form’ to the Sidebar.

You should see the MailChimp subscription form as shown on demo site.