Trying to succes transaction in Tron network to snd usdt using c# and TronNet Nudget package

Question

I have used TronNet nudget packages version 0.2.0 but there is always some bug. So I collected the method based on documentation and some other examples.

I have been trying to get simply transfer usdt assets using tron network, it seems packages not working well.Here one of the many transfer trial

public static async Task TransferTrc20Token(string tokenContractAddress, string walletAddress,
    string privateKey, string toAddress, decimal amount)
        {
            // Create the transfer contract
            var transferContract = new TransferContract
            {
                OwnerAddress = ByteString.CopyFrom(Base58Encoder.DecodeFromBase58Check(walletAddress)),
                ToAddress = ByteString.CopyFrom(Base58Encoder.DecodeFromBase58Check(toAddress)),
                Amount = (long)(amount * 1000000m)
            };

            // Create the transaction
            var transaction = new Transaction
            {
                RawData = new Transaction.Types.raw
                {
                    Contract = { new Transaction.Types.Contract
                    {
                        Type = Transaction.Types.Contract.Types.ContractType.TransferContract,
                        Parameter = Google.Protobuf.WellKnownTypes.Any.Pack(transferContract)
                    }},
                    Timestamp = DateTimeOffset.Now.ToUnixTimeMilliseconds(),
                    Expiration = DateTimeOffset.Now.AddHours(1).ToUnixTimeMilliseconds()
                }
            };

            // Sign the transaction
            transaction = SignTransaction(transaction, privateKey);

            // Serialize the transaction
            var serializedTransaction = transaction.ToByteArray();

            // Convert the serialized transaction to hexadecimal string
            var transactionHex = BitConverter.ToString(serializedTransaction).Replace("-", "");

            // Create the REST client
            var client = new RestClient("https://api.trongrid.io/wallet/easytransfer");
            var request = new RestRequest();
            request.Method = Method.Post;
            request.AddHeader("Accept", "application/json");
            request.AddHeader("Content-Type", "application/json");
            request.AddParameter("application/json", "{\"transaction\":\"" + transactionHex + "\"}", ParameterType.RequestBody);

            // Send the request
            var response = await client.ExecuteAsync(request);

            if (response.IsSuccessful)
            {
                // Handle successful response
                Console.WriteLine("Transfer successful");
            }
            else
            {
                // Handle error response
                Console.WriteLine("Transfer failed: " + response.ErrorMessage);
            }
        }

        private static Transaction SignTransaction(Transaction transaction, string privateKey)
        {
            byte[] privateKeyBytes;
            if (privateKey.Length == 64)
            {
                privateKeyBytes = StringToByteArray(privateKey);
            }
            else
            {
                // Decode private key from Base58Check format
                privateKeyBytes = TronNet.Crypto.Base58Encoder.DecodeFromBase58Check(privateKey);
            }

            var ecKey = new ECKey(privateKeyBytes, true);
            var rawdata = transaction.RawData.ToByteArray();
            var hash = rawdata.ToSHA256Hash();
            var signature = ecKey.Sign(hash).ToByteArray();

            transaction.Signature.Add(ByteString.CopyFrom(signature));

            return transaction;
        }

        private static byte[] StringToByteArray(string hex)
        {
            int length = hex.Length;
            byte[] bytes = new byte[length / 2];
            for (int i = 0; i < length; i += 2)
            {
                bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
            }
            return bytes;
        }

To find what is problem? and process transaction in tron network usdt c#,