Warning: require_once(vendor/autoload.php): Failed to open stream: No such file or directory in /www/wwwroot/xc2/Database.php on line 3

Fatal error: Uncaught Error: Failed opening required 'vendor/autoload.php' (include_path='.:') in /www/wwwroot/xc2/Database.php:3 Stack trace: #0 /www/wwwroot/xc2/index.php(3): require_once() #1 {main} thrown in /www/wwwroot/xc2/Database.php on line 3