How to add St.ScrollView to Gnome shell Extension

I did try your solution but i get the following error. I don’t understand what I am missing.

const scrollView = new St.ScrollView({
        overlay_scrollbars:true, 
        hscrollbar_policy:2, 
        enable_mouse_scrolling: true, 
        x_expand: true, 
        y_expand: true,
          
         });   
       
      this._indicator.menu.box.add_child(scrollView);  
      
     const section = new PopupMenu.PopupMenuSection();
     scrollView.set_child(section.actor);
          
     
       for (let i = 0; i<30; i++) {    
     
         let pmItem = new PopupMenu.PopupMenuItem("This is item "+ i,{});
         section.addMenuItem(pmItem);
      
         }   
             
        Main.panel.addToStatusArea(indicatorName, this._indicator);
    
    }


popupmenu_error