using System;

using System.Text.Json;

using System.Text.Json.Serialization;

[Flags]

public enum ValuesEnum {

    Borrow = 10,

    Lend = 20

}

public class ObjectWithEnum {

    public ValuesEnum Values { get; set;}

}

public class Program

{

    public static void Main()

    {

        var options = new JsonSerializerOptions

        {

            WriteIndented = true,

            Converters =

            {

                new JsonStringEnumConverter(JsonNamingPolicy.CamelCase)

            }

        };

        var obj = new ObjectWithEnum{ Values = ValuesEnum.Lend | ValuesEnum.Borrow };

        string jsonString = JsonSerializer.Serialize(obj, options);

        Console.WriteLine(obj.Values);

        Console.WriteLine(jsonString);

        var dObj = JsonSerializer.Deserialize<ObjectWithEnum>(jsonString, options);

        Console.WriteLine(obj.Values);

        var isLend = (dObj.Values & ValuesEnum.Lend) == ValuesEnum.Lend;

        var isBorrow = (dObj.Values & ValuesEnum.Borrow) == ValuesEnum.Borrow;

        Console.WriteLine(nameof(isLend) + " " + isLend);

        Console.WriteLine(nameof(isBorrow) + " " + isBorrow);

    }

}