<?php
$listmenu = get_nav_menu_locations();
$menu = wp_get_nav_menu_items($listmenu['link-menu']);
if ($menu != null) {
?>
<div class="card card-primary">
  <div class="card-header"><i class="fa fa-link"></i> Liens</div>
  <div class="card-menu">
    <?php
      $menu = wp_get_nav_menu_items( 'link-menu');
        foreach ($menu as $menuElement) {
          echo '<a href="' . $menuElement->url . '" class="menu-element">'. $menuElement->title . '</a>';
        }
      ?>
  </div>
</div>
<?php
}
?>