athena.fb-infra.uk/page-blocks/nav-menu.php

<?php

echo '<div class="dropdown">';
echo '  <button onclick="myFunction()" class="dropbtn">Menu</button>';
echo '  <div id="myDropdown" class="dropdown-content">';
echo '    <a class="dropdown-first" href="/">Home</a>';
echo '    <a href="/issue.php">Report Issue</a>';
echo '    <a href="/help.php">Help</a>';
echo '  </div>';
echo '</div>';