Warning: require(/var/www/html/app/config/config.php): Failed to open stream: Permission denied in /var/www/html/index.php on line 16

Fatal error: Uncaught Error: Failed opening required '/var/www/html/app/config/config.php' (include_path='.:/usr/local/lib/php') in /var/www/html/index.php:16 Stack trace: #0 {main} thrown in /var/www/html/index.php on line 16