Goggle APIS with C # through proxy

I'm trying to connect to the Google drive through Google.apis but here in my service has a proxy and when I try to get the credential it gives error requesting proxy authorization. (opened browser accessed a page it asks for password, if you close the browser and open it again it will ask again). I have tried to put proxy in the config but it does not work. so much that I can not even log my account in Visual Studio it asks for email and password but then it gives error that authentication in the proxy is required. Has anyone had this? Do you have a solution? I already looked at several cases in the stackflow pt and en and nothing solved. Releasing in the proxy is not an option unfortunately.

Follow the code that causes the error. occurs when it goes into the GoogleWebAuthorizationBroker.AuthorizeAsync to connect. ...

using (var stream = new FileStream(@"D:\client_secret.json", FileMode.Open, FileAccess.Read))
            {
                String FolderPath = @"D:\";
                String FilePath = Path.Combine(FolderPath, "DriveServiceCredentials.json");
                credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
                    GoogleClientSecrets.Load(stream).Secrets,
                    Scopes,
                    "user",
                    CancellationToken.None,
                    new FileDataStore(FilePath, true)).Result;
            }