If it is a CMB credit card, you can set the credit card transaction password through online banking (popular version and professional version) and mobile banking. The specific process is as follows:

Online Banking: Select Card Management → Transaction Password Management → Transaction Password Setting.

Mobile Banking: Select "My → All → Credit Card → Card Management → Transaction Password Management → Transaction Password Settings" and click this setting.

Telephone banking: dial the credit card service hotline 4008205555 to verify your identity, press 3, and then press 3 to enter "transaction password setting and modification" to enable this function.