Fatal error: Uncaught Error: Class 'Nexmo\Client\Callback\Callback' not found in /var/www/microservices/vendor/nexmo/client-core/src/Message/Callback/Receipt.php:12
Stack trace:
#0 {main}
thrown in /var/www/microservices/vendor/nexmo/client-core/src/Message/Callback/Receipt.php on line 12