Int32 unixTimestamp = (Int32)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1))).TotalSeconds;
 Console.Write(unixTimestamp);
 var currentTimeUn = unixTimestamp.ToString();
string json = "{ "Method": "GetShippedOrders","Params": { "DateMin": 1575158400, "DateMax": {currentTimeUn} }}";

如何将CurrentTimeUn传递给DateMax？