import QtQuick
import QtQuick.Layouts
import QtQuick.Controls.Windows

ApplicationWindow {
width: 400
height: 400

GridLayout {
columns: 2

   DayOfWeekRow {
       locale: grid.locale

       Layout.column: 1
       Layout.fillWidth: true
   }

   WeekNumberColumn {
       month: grid.month
       year: grid.year
       locale: grid.locale

       Layout.fillHeight: true
   }

   MonthGrid {
       id: grid
       month: Calendar.December
       year: 2015
       locale: Qt.locale("en_US")

       Layout.fillWidth: true
       Layout.fillHeight: true
   }

}
}

I am using above code to create calender in Qt 6.6.0 (Qt13.0.0) but i am getting below errors that
‘MonthGrid’ is not a type
‘WeekNumberColumn’ is not a type
‘DayOfWeekRow’is not a type.

I am not getting how to resolve this issue? Do i need to add anything extra in .pro file?
please guide me