Firebase C#

private FirebaseClient Auth()

{

    var firebaseClient = new FirebaseClient(_URL,

        new FirebaseOptions

        {

            AuthTokenAsyncFactory = () => Task.FromResult(_FireBaseApiKey)

        });

    return firebaseClient;

}

public async Task<Dictionary<string, T>> ListLimitLast<T>(string table, string filterKey, string filterValue, int limitLast)

 {

     var firebase = Auth();

     var result = await firebase

         .Child(_Database)

         .Child(table)

         .OrderBy("DriverStaff/UserName")

         .EqualTo(filterValue)

         .LimitToLast(limitLast)

         .OnceSingleAsync<Dictionary<string, T>>();

     return result;

 }

use dictionary because ID is parent, object is child.