Fatal error: Uncaught Error: Class "GuzzleHttp\Command\Guzzle\Serializer" not found in E:\phpProject\TEST\vat_api_se_client\vendor\qcloud\cos-sdk-v5\src\Serializer.php:13 Stack trace: #0 {main} thrown in E:\phpProject\TEST\vat_api_se_client\vendor\qcloud\cos-sdk-v5\src\Serializer.php on line 13