Your card is never stored — each invoice is paid on its own, through a secure Stripe checkout link created for that invoice.
When you buy a package, your browser is sent to Stripe's secure checkout page, and you enter your card details there. Card numbers are never typed into MarbleMap screens and are never held on MarbleMap's side.
For later invoices, open Settings → Subscription and look at Invoice history. An unpaid invoice shows as Pending, and the Pay button on its row opens a fresh secure checkout link for that invoice. Paid invoices can be downloaded as PDF from the same list.
That is why the Settings → Payment Method tab says "No card is stored": there is no reusable card on file, so there is nothing to add or replace there. The tab is display only.
Payment covers your subscription only. MarbleMap takes no cut of any sale — the goods value between buyer and supplier never passes through the platform; subscriptions are the platform's only revenue.
Also asked as: Do you keep my credit card on file? · Is payment secure, where are my card details held? · How do I pay for my subscription? · How do I change my saved card?