Mobile WeChat official account. Find Zhangjiakou Bank in the WeChat official account, enter the credit card activation page in Zhangjiakou Bank, enter the ID number, credit card number, validity period, CVV2, mobile phone number and SMS verification code, enter the WeChat official account on your mobile phone, and click Apply. Credit cards refer to various media that record cardholder account information, have bank credit lines and overdraft functions, and provide cardholders with related banking services.