Fatal error: Uncaught TypeError: PaymentModel::getRefundAccount(): Argument #1 ($userSno) must be of type int, null given, called in /home/modern/app/controllers/mypage/PaymentMethodController.php on line 13 and defined in /home/modern/app/models/mypage/PaymentModel.php:7 Stack trace: #0 /home/modern/app/controllers/mypage/PaymentMethodController.php(13): PaymentModel->getRefundAccount() #1 /home/modern/public/mypage/payment_method.php(4): PaymentMethodController->payment_method() #2 {main} thrown in /home/modern/app/models/mypage/PaymentModel.php on line 7