Plugins html php

I am struggling with using plugins for dropdown menus. My project is a php mysql project (not using composer) hosted on Bluehost and currently using Bootstrap css framework. I am refactoring to use Foundation. I am new to Foundation. I am looking for a good tutorial for using the dropdown menu plugin. I have installed Foundation using the CDN links and have included the js files at the bottom of the page as instructed in the docs but can’t seem to get the dropdown to work. I know it is something simple I am missing. Any assistance is appreciated.

<?php 
echo "<div class='top-bar'>"; 
 echo "<div class='top-bar-left'>";
 echo " <li class='menu-text' style='font-weight:bolder;'>$pageName</li>";

 echo "</div>";

 echo "<div class='top-bar-right'>";    
 echo "<ul class='menu align-right'>";

echo " <li><a class='' style='font-size:14px' href='#'>Home</a></li>";

 
  echo " <li><a class='#'>Main Item</a>
 
         <ul class='dropdown menu' data-dropdown-menu>
             <li><a href='#'>Item 1</a></li>
             <li><a href='#'>Item 2</a></li>
             <li><a href='#'>Item 3</a></li>
             <li><a href='#'>Item 4</a></li>
         </ul>
  
</li>";

echo "</div>";
echo "</div>";
?>