Fatal error: Uncaught Error: Class "Nexmo\Client\Callback\Callback" not found in /home/rpios/demo-stat.cymdev.com/vendor/nexmo/client/src/Network/Number/Callback.php:33 Stack trace: #0 {main} thrown in /home/rpios/demo-stat.cymdev.com/vendor/nexmo/client/src/Network/Number/Callback.php on line 33