Fatal error: Uncaught Error: Class "Vonage\Client\Credentials\Handler\AbstractHandler" not found in C:\xampp\htdocs\hannoole\PMS\vendor\vonage\client-core\src\Client\Credentials\Handler\KeypairHandler.php:9 Stack trace: #0 {main} thrown in C:\xampp\htdocs\hannoole\PMS\vendor\vonage\client-core\src\Client\Credentials\Handler\KeypairHandler.php on line 9