Hello,
Thanks for your Kind Patience!
Consider using the following code instead replacing the existing codes:
<div class="widget subscribe-widget">
<div class="widget-subscribe-form-result"></div>
<form id="widget-subscribe-form" action="include/subscribe.php" method="post" class="mb-0 row">
<div class="col-lg-9">
<input type="email" id="widget-subscribe-form-email" name="widget-subscribe-form-email" class="form-control required email" placeholder="Enter your Email to Subscribe to our Newsletter">
</div>
<div class="col-lg-3">
<button class="button button-rounded m-0 text-center w-100" type="submit">Subscribe</button>
</div>
</form>
<div class="line line-sm"></div>
<div class="row col-mb-30">
<div class="col-lg-3 col-6 widget_links">
<ul>
<li><a href="#">Home</a></li>
<li><a href="#">About</a></li>
<li><a href="#">FAQs</a></li>
<li><a href="#">Support</a></li>
<li><a href="#">Contact</a></li>
</ul>
</div>
<div class="col-lg-3 col-6 widget_links">
<ul>
<li><a href="#">Shop</a></li>
<li><a href="#">Portfolio</a></li>
<li><a href="#">Blog</a></li>
<li><a href="#">Events</a></li>
<li><a href="#">Forums</a></li>
</ul>
</div>
<div class="col-lg-3 col-6 widget_links">
<ul>
<li><a href="#">Corporate</a></li>
<li><a href="#">Agency</a></li>
<li><a href="#">eCommerce</a></li>
<li><a href="#">Personal</a></li>
<li><a href="#">One Page</a></li>
</ul>
</div>
<div class="col-lg-3 col-6 widget_links">
<ul>
<li><a href="#">Restaurant</a></li>
<li><a href="#">Wedding</a></li>
<li><a href="#">App Showcase</a></li>
<li><a href="#">Magazine</a></li>
<li><a href="#">Landing Page</a></li>
</ul>
</div>
</div>
</div>
and also please use only the include/subscribe.php File where you add your Mailchimp API key and List ID. If you would like to receive the responses of the Subscribe Form to your Email, then simply replace the action Attribute of the <form> with this: action="include/subscribe-email.php" and then add your Email Address inside.
This will definitely work fine. Hope this Helps!
Let us know if we can help you with anything else or if you find any further issues.