Warning: require_once(404.php): Failed to open stream: No such file or directory in /var/www/html/index.php on line 18

Fatal error: Uncaught Error: Failed opening required '404.php' (include_path='.:/usr/local/lib/php') in /var/www/html/index.php:18 Stack trace: #0 {main} thrown in /var/www/html/index.php on line 18