Fatal error: Uncaught Error: Interface "Vonage\Entity\JsonSerializableInterface" not found in /home/demoweb/public_html/placementship-backend/vendor/nexmo/client-core/src/Account/Balance.php:29 Stack trace: #0 {main} thrown in /home/demoweb/public_html/placementship-backend/vendor/nexmo/client-core/src/Account/Balance.php on line 29