As an organizer, do I need to add my bank card so players can pay me by card?

No. You don’t attach a card or a payment account to receive money, and you don’t link anything to a game: there is no screen for it. Players who pay online pay through Playbox, the money lands in your Playbox wallet after the game (with the Playbox fee charged there), and you withdraw it separately: Wallet, “Available for pay out”, “Pay out” (minimum $5), to a bank account through Stripe or Wise.

Optional and separate: if you also want players to pay you directly, you can show them a bank account or a QR code from Settings, “Finance settings”, “Transfer details”. It is not a payment account linked to Playbox or to a game: players only see it at checkout when they pay in cash or by transfer, and no money passes through Playbox there.

Which methods players see in your games comes from “Accepted Payment Methods” in the same Finance settings: “Both Online & Cash”, “Only Online” or “Only Cash”. The game form itself has no payment step and no “Playbox wallet” or “Add card” option, so nothing is missing there, and as the organizer nothing restricts you. “Payment cards” in Finance settings are cards you pay with yourself.