Postmand code not working

I’m using postman stand alone app(v6.4.2). I’m successfully able to call client api through postman. But when I try to same with C#(RestSharp) code snippet from ‘Code’ section in my .net app. It won’t act the same, rather it returns me 401(Unauthorized) from client.

Details

Screen - 1: You can find highlighted portion, where 200(OK) status received while call api via postman. In the popup same api code snippet available via postman. When I’m trying to run that code in my application it won’t work and returned 401(Unauthorized).
Screen - 2 : This is the fiddler screenshot which having provided request header using postman call.
Screen - 3 : Code provided by postman(from Screen - 1) execute from my application received this result in fiddler.
Screen - 4 : My application which I’m debugging code provided by postman(from Screen - 1).