The method is as follows: 1. Open the mobile banking APP and log in to your credit card account. Find the credit card bill or transaction record page and find the transaction record for which the security code needs to be queried.

2. Click on the transaction record to view detailed information, including transaction date, transaction amount, merchant name, etc.

3. On the detailed information page, find the security code column and check whether the security code for the transaction is correct.