How does a customer attach a saved card for auto-renewal?

To enable auto-renewal, a customer attaches a saved card to the subscription. Saved cards are stored as PCI-safe tokens (a StoredPaymentMethod holds only an opaque provider token plus safe display info like brand and last four digits — never raw card data). Once a card is attached and the subscription is in Stored mode, the daily sweep charges that token each cycle automatically. The…

To enable auto-renewal, a customer attaches a saved card to the subscription. Saved cards are stored as PCI-safe tokens (a StoredPaymentMethod holds only an opaque provider token plus safe display info like brand and last four digits — never raw card data). Once a card is attached and the subscription is in Stored mode, the daily sweep charges that token each cycle automatically. The customer can manage their saved cards (add, set default, remove — though a card in use by an active subscription is protected from casual removal) so auto-renew is under their control.