Twenty Thirteen Integration Guide

Manual Integration: WP_nav_menu

Replace the following code in the header.php file:

<nav id="site-navigation" class="navigation main-navigation" role="navigation">
   <button class="menu-toggle"><?php _e( 'Menu', 'twentythirteen' ); ?></button>
   <a class="screen-reader-text skip-link" href="#content" title="<?php esc_attr_e( 'Skip to content', 'twentythirteen' ); ?>"><?php _e( 'Skip to content', 'twentythirteen' ); ?></a>
   <?php wp_nav_menu( array( 'theme_location' => 'primary', 'menu_class' => 'nav-menu' ) ); ?>
   <?php get_search_form(); ?>
</nav>
<!-- #site-navigation -->

With the following –

<?php wp_nav_menu( array( 'theme_location' => 'primary', 'menu_class' => 'nav-menu' ) ); ?>

Take note: Menu location

If you choose to use the wp_nav_menu example, remember to set your menu location under the settings tab in the HeroMenu. Navigate to Hero Menu » Select Menu » Settings » Menu Integration

Example of menu location settings: