Where can I get the social security card for Renshou account?

This kind of situation is usually handled in a bank.

If you are an insured payer, bring your ID card to the local social security cooperative bank. Adult: I carry the original ID card. Minors: Any guardian must bring the original ID card, the original minor household register, the original birth certificate and the recent one-inch color photo on a white background. Go to the bank to handle it.