WordPress - How to show a nav menu_item only to users who are logged in

functions.php

<?php

add_filter( 'wp_setup_nav_menu_item', function ( $menu_item ) {
	if ( ! is_user_logged_in() &&
	     in_array( 'private', $menu_item->classes )
	) {
		$menu_item->_invalid = true;
	}

	return $menu_item;
} );