Unauthorized Error:call flipkart seller api for order Search

Question

string frmDateTime = txtfromdate.Text;

string Todate = txtTodate.Text;

 

 

var frmstr = HttpUtility.ParseQueryString(frmDateTime);

var Tostr = HttpUtility.ParseQueryString(Todate);

 

 

var uri = "https://api.flipkart.net/sellers/v2/orders/search/orderDate?fromDate=" + frmstr + "&toDate =" + Tostr;

var client = new WebClient();

client.Headers.Add("X", "Y");

var inforesponse = client.DownloadString(new Uri(uri));  //error-- The remote server returned an error: (401) Unauthorized.

if (inforesponse != null)

{

}