Answer by Pramod Lawate for Calling WEB API with basic authentication in C#

(Basic Authentication) Here is the other solution to call Authenticated API

 class Program
{
    static void Main(string[] args)
    {
        BaseClient clientbase = new BaseClient("https://website.com/api/v2/", "username", "password");
        BaseResponse response = new BaseResponse();
        BaseResponse response = clientbase.GetCallV2Async("Candidate").Result;
    }


    public async Task<BaseResponse> GetCallAsync(string endpoint)
    {
        try
        {
            HttpResponseMessage response = await client.GetAsync(endpoint + "/").ConfigureAwait(false);
            if (response.IsSuccessStatusCode)
            {
                baseresponse.ResponseMessage = await response.Content.ReadAsStringAsync();
                baseresponse.StatusCode = (int)response.StatusCode;
            }
            else
            {
                baseresponse.ResponseMessage = await response.Content.ReadAsStringAsync();
                baseresponse.StatusCode = (int)response.StatusCode;
            }
            return baseresponse;
        }
        catch (Exception ex)
        {
            baseresponse.StatusCode = 0;
            baseresponse.ResponseMessage = (ex.Message ?? ex.InnerException.ToString());
        }
        return baseresponse;
    }
}


public class BaseResponse
{
    public int StatusCode { get; set; }
    public string ResponseMessage { get; set; }
}

public class BaseClient
{
    readonly HttpClient client;
    readonly BaseResponse baseresponse;

    public BaseClient(string baseAddress, string username, string password)
    {
        HttpClientHandler handler = new HttpClientHandler()
        {
            Proxy = new WebProxy("http://127.0.0.1:8888"),
            UseProxy = false,
        };

        client = new HttpClient(handler);
        client.BaseAddress = new Uri(baseAddress);
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        var byteArray = Encoding.ASCII.GetBytes(username + ":" + password);

        client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Basic", Convert.ToBase64String(byteArray));

        baseresponse = new BaseResponse();

    }
}