How to pass a List from one page to another.

I'm having this issue and i'm stumped. I'm able to pass and received single object but If I try to pass a list, the data is not going to the second page.

Here is my OrderList Page

  [BindProperty]
    public IList<Orders> Orders{ get; set; }
 public ActionResult OnPost()
        {
//get modified data. 
var orderList = Orders
 return RedirectToPage("/ConvertToCsv", orderList );
       }

on my ConvertToCsv page. 
  public void OnGet(IList<Orders> orderList )
        {
//do something with list. 
}

But the orderlist on OnGet is null. 
I tested by passing a single record like
 public ActionResult OnPost()
        {

 return RedirectToPage("/ConvertToCsv", new{orderId= "test"});
       }

  public void OnGet(string orderId )
        {
//This works.  
}

What am I doing wrong?