var jsonString = @"{}";
var jsonDoc = JsonSerializer.Deserialize<Dictionary<string, object>>(jsonString);
jsonDoc.Add("Name", "Khurshid Ali");
Console.WriteLine(JsonSerializer.Serialize(jsonDoc));
var dynamicObject = new ExpandoObject() as IDictionary<string, Object>;
foreach (var property in properties) {
dynamicObject.Add(property.Key,property.Value);
}