add_filter('wp_nav_menu_items', 'add_search_form', 10, 2);
function add_search_form($items, $args) {
if( $args->theme_location == 'MENU-NAME' )
$items .= '<ul>
<li class="search">
<form id="searchform" role="search" action="'.home_url( '/' ).'" method="get"><input id="s" name="s" type="text" value="search"><input id="searchsubmit" type="submit" value="'. esc_attr__('Search') .'"></form>
</li>
</ul>';
return $items; } Reference Links
https://wpdynamic.com/wordpress-developer/wordpress-code-snippets/how-to-add-a-wordpress-search-form-to-a-specific-wp_nav_menu/
