Fatal error: Uncaught Error: Interface "Magento\Payment\Gateway\Response\HandlerInterface" not found in /home/airtimer/public_html/vendor/amzn/amazon-pay-module/Gateway/Response/CompleteSaleHandler.php:33 Stack trace: #0 {main} thrown in /home/airtimer/public_html/vendor/amzn/amazon-pay-module/Gateway/Response/CompleteSaleHandler.php on line 33