How to apply sorting for the new items added in SfDataGrid?

public MainPage()

{

      InitializeComponent();

      viewModel = new ViewModel();

      dataGrid.ItemsSource = viewModel.OrdersInfo;

      dataGrid.AllowSorting = true;

      dataGrid.GridLoaded += DataGrid_GridLoaded;

      dataGrid.SortColumnDescriptions.Add(new SortColumnDescription() { ColumnName = "EmployeeID", SortDirection = ListSortDirection.Descending });

}

private void DataGrid_GridLoaded(object sender, GridLoadedEventArgs e)

{

      dataGrid.View.LiveDataUpdateMode = LiveDataUpdateMode.AllowDataShaping;

}