在 binace 上下订单时获取对象引用错误

如何解决在 binace 上下订单时获取对象引用错误

我正在尝试在币安测试中下订单，但出现异常。

var client = TestHelpers.CreateClient( new BinanceClientOptions("",Common.apiURL,"")
        {
                ApiCredentials = new ApiCredentials(Common.apiKey,Common.apiSecret),AutoTimestamp = false,LogVerbosity= LogVerbosity.Debug,LogWriters= new List<TextWriter> { (new StreamWriter(Path.Combine(Application.StartupPath,"logs.txt")))}



            });
            
            // act
            var result = client.FuturesUsdt.Order.PlaceOrder("BTCUSDT",OrderSide.Buy,OrderType.Limit,timeInForce: TimeInForce.GoodTillCancel,quantity: 1,price: 2000);

例外： System.NullReferenceException: '未将对象引用设置为对象的实例。'

这个异常最初是在这个调用栈上抛出的：【外码】 Binance.Net.SubClients.Futures.BinanceClientFuturesOrder.PlaceOrderAsync(string,Binance.Net.Enums.OrderSide,Binance.Net.Enums.OrderType,decimal?,Binance.Net.Enums.PositionSide?,Binance.Net.Enums.TimeInForce? 、bool?、decimal?、string、decimal?、decimal?、decimal?、Binance.Net.Enums.WorkingType?、bool?、Binance.Net.Enums.OrderResponseType?、int?、System.Threading.CancellationToken) 在 BinanceClientFuturesOrder .cs

APIBaseURL：https://testnet.binancefuture.com