Call Github Graphql Api using c#

Program.cs

class Program
{
    static async Task Main(string[] args)
    {
        var httpClient = new HttpClient
        {
            BaseAddress = new Uri("https://api.github.com/graphql")
        };

        httpClient.DefaultRequestHeaders.Add("User-Agent", "MyConsoleApp");

        string basicValue = Convert.ToBase64String(Encoding.UTF8.GetBytes($"{Configs.GithubAccount}:{Configs.PersonalToken}"));
        httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", basicValue);

        var queryObject = new
        {
            query = @"query { 
                viewer { 
                login
                }
            }",
            variables = new { }
        };

        var request = new HttpRequestMessage
        {
            Method = HttpMethod.Post,
            Content = new StringContent(JsonConvert.SerializeObject(queryObject), Encoding.UTF8, "application/json")
        };

        dynamic responseObj;

        using (var response = await httpClient.SendAsync(request))
        {
            response.EnsureSuccessStatusCode();

            var responseString = await response.Content.ReadAsStringAsync();
            responseObj = JsonConvert.DeserializeObject<dynamic>(responseString);
        }

        Console.WriteLine(responseObj.data.viewer.login);
        Console.ReadLine();
    }
}