Fatal error: Uncaught Error: Class "Google\Auth\HttpHandler\Guzzle6HttpHandler" not found in C:\xampp\htdocs\cms-propay\vendor\google\auth\src\HttpHandler\Guzzle7HttpHandler.php:19 Stack trace: #0 {main} thrown in C:\xampp\htdocs\cms-propay\vendor\google\auth\src\HttpHandler\Guzzle7HttpHandler.php on line 19