How to properly authenticate my user's credentials

See more:

C#

https://developers.credly.com/getting-started

I'm trying to do what is being stated on "Get familiar with authentication"

I'm still getting a 401 error after trying my code below. All I ever wanted is to make it work. My username and password is working properly and I read the everything stated on this site for Authorization field. Please help

https://en.wikipedia.org/wiki/Basic_access_authentication#Protocol

What I have tried:

string encoded = Convert.ToBase64String(Encoding.GetEncoding("ISO-8859-1").GetBytes(email_address + ":" + password));

                    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(end_Point);
                    request.Headers.Add("X-Api-Key", credly_api_key);
                    request.Headers.Add("X-Api-Secret", credly_app_key);
                    request.Headers.Add("Authorization", "Basic " + encoded);