Hi, I just create a sample for you. And it works under a sample test.

Don`t remember to add

using Newtonsoft.Json;

public class JsonObjects{public authObject authObject;public billObj billObj;}public class authObject {public string userName;public string password;public string baladyCode;public string amanaCode;}public class billObj{public string billNumber;public string billCreationDate;public List
     
       billDetails;//public billDetail[] billDetails;}public class billDetails{public int depId;public int billValue;}string json =@"{authObject:{userName:7070,password:123,baladyCode:07,amanaCode:061},billObj:{billNumber:'0611138000302',billCreationDate:'07-01-1438',billDetails:[{depId:11006,billValue:1}]}}";public Form1(){InitializeComponent();JsonObjects objs = JsonConvert.DeserializeObject
      
       (json);}