Fatal error: Uncaught Error: Interface 'GuzzleHttp\Promise\PromisorInterface' not found in /home/wittyly/public_html/staging/wittymanager-api/vendor/guzzlehttp/guzzle/src/Pool.php:20 Stack trace: #0 {main} thrown in /home/wittyly/public_html/staging/wittymanager-api/vendor/guzzlehttp/guzzle/src/Pool.php on line 20