How to get facebook access token using get request in ASP.Net

Hi,

I want to retrieve user access token through get method. Able to retrive app access token easliy with below get command :

https://graph.facebook.com/oauth/access_token?client_id={0}&client_secret={1}&grant_type=client_credentials.

But not able to find similar command for user access token in below facebook url.

https://developers.facebook.com/docs/facebook-login/manually-build-a-login-flow