Offchain cancel a single order, offer or listing, by its order hash when protected by the SignedZone. Protocol and Chain are required to prevent hash collisions. An offchain cancel stops OpenSea from issuing new fulfillment signatures for the order, but a fulfillment signature issued before the cancel stays valid until it expires (up to 5 minutes after it was issued), and a buyer holding one can still fill the order until then. The response field last_signature_issued_valid_until reports when the last issued signature expires. To stop fills without waiting for that signature to expire, cancel the order onchain; use the get order cancellation actions endpoint to build that transaction. The order stays fillable until the onchain cancel transaction is confirmed. A recently created listing or offer may need to be cancelled onchain; if this endpoint rejects it, use the get order cancellation actions endpoint to build the onchain transaction.