System.NullReferenceException

[Kei-OHKAWA]

I just downloaded it.
I get an error when I build and run it.

[BinanceBot.cs]
namespace BinanceMarketMaker.BusinessLogic
public class BinanceBot

        public BinanceBot(BinanceClient binanceClient, SynchronizationContext context)
        {
            this.context = context;
            Orders = new ObservableCollection<Order>();

            this.binanceClient = binanceClient;
            **var webRequest = this.binanceClient.GetExchangeInfo();**
            symbols = webRequest.Data.Symbols.ToList();
        }

webRequest.Data is Null.

webRequest.Error.Message is 'Error deserializing data'

Can you tell me what is the cause?

I have set the API key and secret key.
What do I enter for the license and fee?