How to get account Balance using TronNet?

Question

TronNet has IContractClient to get Usdt balance, but I can't get the TRX(Native Coin) balance.

https://github.com/stoway/TronNet

I've Found GetAccountBalance in TronNet.Protocol.Wallet but this code returns Grpc.Core.RpcException: Status(StatusCode="Unknown", Detail="") Exception

    var options = new TronNetOptions()
 {
     Network = TronNetwork.MainNet,
     Channel = new GrpcChannelOption { Host = "grpc.trongrid.io", Port = 50051 },
     SolidityChannel = new GrpcChannelOption { Host = "grpc.trongrid.io", Port = 50052 },
     ApiKey = "80a8b20f-a917-43a9-a2f1-809fe6eec0d6"
 };
 var grpcChannelClient = new GrpcChannelClient(null, options);
 var walletClient = new WalletClient(grpcChannelClient, options);
 var transactionClient = new TransactionClient(walletClient, options);
 var wallet = walletClient.GetProtocol();

 var ownerAddressBytes = Base58Encoder.DecodeFromBase58Check(publicAddress);
 var accountIdentitfier = new AccountIdentifier();
 var blockIdentifier = new BlockIdentifier();
 
 accountIdentitfier.Address = ByteString.CopyFrom(ownerAddressBytes);
 blockIdentifier.Hash = ByteString.CopyFromUtf8("latest");
 var accountBalanceRequest = new AccountBalanceRequest { AccountIdentifier = accountIdentitfier, BlockIdentifier = blockIdentifier};

 var response = await wallet.GetAccountBalanceAsync(accountBalanceRequest, walletClient.GetHeaders());
 return response.Balance;