Warning: require_once(/var/www/html/config.php): Failed to open stream: Permission denied in /var/www/html/index.php on line 30

Fatal error: Uncaught Error: Failed opening required 'config.php' (include_path='.:/usr/local/lib/php') in /var/www/html/index.php:30 Stack trace: #0 {main} thrown in /var/www/html/index.php on line 30