Fatal error: Uncaught Error: Class 'Vonage\Client\Credentials\AbstractCredentials' not found in C:\xampp\htdocs\kit\vendor\vonage\client-core\src\Client\Credentials\Keypair.php:28 Stack trace: #0 {main} thrown in C:\xampp\htdocs\kit\vendor\vonage\client-core\src\Client\Credentials\Keypair.php on line 28