title: Skype bot attachment download in bot builder v4
body: <p>I'm trying to download an image uploaded in Skype bot using Bot Builder v4. I've retrieved the JwtSecurityToken for Authorization when using httpClient to download the image. But sometimes I'm receiving unauthorized error.</p>
  
  <pre><code>var context = stepContext.Context;
  var channelId = context.Activity.ChannelId;
  
  if (channelId.Equals("skype"))
  {
      using (var connectorClient = (ConnectorClient)context.TurnState.First(x =&gt; x.Key.Equals("Microsoft.Bot.Connector.IConnectorClient")).Value)
      {
          if (connectorClient?.Credentials != null)
          {
             var credentials = (MicrosoftAppCredentials)connectorClient.Credentials;
             var authToken = await new MicrosoftAppCredentials(credentials.MicrosoftAppId, credentials.MicrosoftAppPassword).GetTokenAsync().ConfigureAwait(false);
          }
      }
  }
  </code></pre>