Security Check
1Procedures to Prevent Forgery and Falsification (Essential)
Apart from the good_mny value delivered to the payment window, please pass the actual amount (ordr_mny) value to the API server when requesting authorization.
Comparing the amount transferred after the payment with the amount of Merchant DB and implement a logic to request cancellation if the value varies.
Please be sure to check the corresponding function in case of the future forgery risk of payment amount.