How to add Social Icons to Genesis Menu

//ADD SOCIAL ICON TO GENESIS MENU
function wdm_add_menu_items( $menu, $args ) {
    // check if it is the 'primary' navigation menu
    if ( 'primary' === $args->theme_location )
    {
      // add the search form
      ob_start();
      get_search_form();
      $search = ob_get_clean();
      $menu  .= '<li id="menu-item-125" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-125">
                    <a href="#" target="_blank">
                        <i class="fb-icon fab fa-facebook-f"></i>
                    </a>
                </li>';
    }
    return $menu;
}
add_filter( 'wp_nav_menu_items', 'wdm_add_menu_items', 10, 2 );