gistfile1.cs

public void Ping(string authorizationCode) {
	var client = new WebClient { BaseAddress = string.Format("ACS_URL") };

	var values = new NameValueCollection
	{
		{"code", authorizationCode},
		{"grant_type", "authorization_code"},
		{"redirect_uri", "REDIRECT_URI"},
		{"client_id", "SERVICE_USERNAME"},
		{"client_secret", "SERVICE_USERKEY"},
		{"scope", "RELYING_PARTY_REALM"},
	};

	var responseBytes = client.UploadValues("/v2/OAuth2-13", "POST", values);
	var response = Encoding.UTF8.GetString(responseBytes);
	var result = JsonConvert.DeserializeObject<JwtToken>(response);
	var accessToken = result.AccessToken;

	var req = (HttpWebRequest)WebRequest.Create("WEB_APP_URL");

	req.Headers.Add("Authorization", string.Format("Bearer {0}", accessToken));
			
	var response2 = (HttpWebResponse)req.GetResponse();
}