BitPay c# SDK Error : Unauthorized sin -

i implementing bitpay api using c# sdk.

i doing according csharp-bitpay-client , bitpay c# client library configuration unfortunately not achieving this.

every time stuck at:

bitpay bitpay = new bitpay(); 

i tried:

eckey key = keyutils.createeckey(); this.bitpay = new bitpay(key); 

but key generates again stuck here:

this.bitpay = new bitpay(key); 

every time getting message bitpay server:

{"error":"unauthorized sin"} 

any 1 have idea it?

and not seeing public key on dashboard. 1 know why public key not showing.

thanks