You can go to the credit card website of CCB and click "Credit Card Online Application" to apply for supplementary cards directly for your family. If the card type applied for is not supported online, you can also apply at CCB outlets. It's also very simple. You only need the main cardholder to go to the outlet together, bring the credit card of the main cardholder and the ID card of the supplementary cardholder, and then fill out a form, which will be signed by all the main cardholders.