SquareUp nonce error

Short message
Square payment error: Error calling Charge: {"errors":[{"category":"INVALID_REQUEST_ERROR","code":"CARD_TOKEN_USED","detail":"Card nonce already used; please request new nonce."}]}.

Full message
Square.Connect.Client.ApiException: Error calling Charge: {"errors":[{"category":"INVALID_REQUEST_ERROR","code":"CARD_TOKEN_USED","detail":"Card nonce already used; please request new nonce."}]}