Full version wouldn't oblige.

[TadyHUN]

Input: blvk3sp@c3
System.Net.WebException: An error occurred while sending the request.
---> System.Net.Http.HttpRequestException: An error occurred while sending the request.
---> System.IO.IOException: The response ended prematurely.
at System.Net.Http.HttpConnection.FillAsync(Boolean async)
at System.Net.Http.HttpConnection.ReadNextResponseHeaderLineAsync(Boolean async, Boolean foldedHeadersAllowed)
at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
--- End of inner exception stack trace ---
at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
at System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)
at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
at System.Net.Http.HttpMessageHandlerStage.Send(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.SocketsHttpHandler.Send(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpClientHandler.Send(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpMessageInvoker.Send(HttpRequestMessage request, CancellationToken cancellationToken)
at System.Net.Http.HttpClient.SendAsyncCore(HttpRequestMessage request, HttpCompletionOption completionOption, Boolean async, Boolean emitTelemetryStartStop, CancellationToken cancellationToken)
at System.Net.Http.HttpClient.Send(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationToken cancellationToken)
at System.Net.HttpWebRequest.SendRequest(Boolean async)
at System.Net.HttpWebRequest.GetResponse()
--- End of inner exception stack trace ---
at System.Net.HttpWebRequest.GetResponse()
at CoubDownloader.Crawler.VerifyIfChannelExists(String channel)
at CoubDownloader.Crawler.DownloadChannelCoubs(String channel)
at CoubDownloader.Crawler.CrawlUrls(String[] categories)
at CoubDownloader.Program.GetCoubs(String input, Configuration configuration)
at CoubDownloader.Program.Main()

(+What is the command to add the token?)

[Bukk94]

@TadyHUN I tried your input. It seems that you are using your Display name instead of username. To download your channel/profile, you need to use your username. This username can be found when you open your profile and you'll look in the URL.
It is something like https://coub.com/username1234. So add just username1234 to the program input. As for the token, you'll be asked by the application to insert it when it needs it.

[TadyHUN]

Thx!