public async Task <TransactionResponse> FinalizeSecureTransactionAsync(string transactionId, AuthenticationUpdateRequest payload, string region = null) { Signature signatureService = GetSignatureService(); string messageSignature = signatureService.Sign(JsonConvert.SerializeObject(payload)); return(await payApi.FinalizeSecureTransactionAsync( CONTENT_TYPE, signatureService.ClientRequestId, GetApiKey(), signatureService.TimeStamp, transactionId, payload, messageSignature, region )); }