Unblock PIN for a physical card

Use this when a cardholder has locked themselves out of their card at the terminal.

A physical card is marked pinBlocked after too many failed PIN attempts, and stops working for in-person and ATM transactions. This clears that block so the existing PIN can be used again. It doesn't change the PIN.

Prerequisites

The card must be physical and activated (PHYSICAL_CARD_NOT_ACTIVATED), and neither blocked nor destroyed. A PIN block is separate from a card block: if the card itself is blocked, this fails with INSTRUMENT_BLOCKED and you need Unblock a card instead.