Tell me how to handle the TRANSACTION_NOT_FOUND error in Check Cashback Details.

For the TRANSACTION_NOT_FOUND error in Check Cashback Details, check the following:
- If merchantCashbackId is wrong, set a correct merchantCashbackId and then execute again.
- If merchantCashbackId is correct, please retry.

Note that when "Check Cashback Details" is executed right after "Give Cashback to User", the TRANSACTION_NOT_FOUND error may occur. We therefore ask you to wait for approximately one second after "Give Cashback to User" to execute "Check Cashback Details."