Fatal error: Uncaught Error: Interface 'GuzzleHttp\Promise\PromiseInterface' not found in D:\xampp\htdocs\psp\backend\vendor\guzzlehttp\promises\src\FulfilledPromise.php:15 Stack trace: #0 {main} thrown in D:\xampp\htdocs\psp\backend\vendor\guzzlehttp\promises\src\FulfilledPromise.php on line 15