My client has created an eCommerce website in Odoo 15. In that website, users create their accounts, provide their credit card details, mobile number, and address to create a profile. Users can store multiple cards.

1 - How can an old card be removed if needed? 
2 - How does the 2-factor authentication (2FA) functionality work in editing security settings? 
3 - How can a promo code for the website be activated?