C # GetResponseAsync (): how to use correctly

I am developing an application using Twitch API and I tried using asynchronous request.

I am testing earlier with a synchronous request, for example:

private async static Task<string> generalRequest(string url, string method, object payload = null, string accessToken = null, API api = API.V5, string clientId = null)
{
    url = appendClientId(url, ClientId);

    var request = WebRequest.CreateHttp(url);
    request.Method = method;
    request.ContentType = "application/json";

    var response = request.GetResponse();
    using (var reader = new StreamReader(response.GetResponseStream()))
    {
        string data = await reader.ReadToEndAsync();
        return data;
    }
}

      

        
        
        
      

    

It works great, but it's not asynchronous.

I tried with the GetResponseAsync()

following:

using (var response2 = await request.GetResponseAsync())
{
    using (var reader = new StreamReader(response2.GetResponseStream()))
    {
        string data = await reader.ReadToEndAsync();
        return data;
    }
}

      

        
        
        
      

    

However, it didn't go through the first using

one and I got these exceptions:

Exception: "System.Net.WebException" in mscorlib.dll

Exception: "System.Exception" in LivestreamerTwitchViewer.exe

Exception levée: "System.Exception" in mscorlib.dll

So what did I do wrong?

How to use it correctly GetResponseAsync()

?

Thanks in advance for your help.