To display the generated custom fields for each menu item, use the Smarty loop method to render the menu (read more).
Example of displaying menu items with icons (an additional field {$item.field_icon} is provided, which can be used to retrieve the desired image file):
<nav class="menu">
{foreach $items as $item}
<div class="menu-item">
<a href="{$item.url}">
<img src="{$item.field_icon}"/>
{$item.name}
</a>
</div>
{/foreach}
</nav>
