Hey im trying to upload image to server but keep getting 503 service unavailable or error code 1200..Cuz i know server too busy but the others can upload their images succesfully what am i doing wrong?

Here is my code;

private async Task UploadImage()
{
    while (true)
    {
        try
        {

            var request = new HttpRequestMessage(HttpMethod.Post, "Submission/Home/AjaxPhotoUpload");
            var content = new MultipartFormDataContent
        {
            {
              new StreamContent(File.OpenRead(_citizen.PhotoPath)), _citizen.imageUpload , _citizen.FileNameWithExt},
            { new StringContent("-1"), "subDocIndex" }
        };
            request.Content = content;
            var response = await _httpClient.SendAsync(request);
            if (response.IsSuccessStatusCode)
            {

                Console.WriteLine("uploaded image");                
                break;
            }
            else
            {
                Console.WriteLine("FAILED to upload image");
            }
            // var result = await response.Content.ReadAsStringAsync();

        }
        catch (Exception e)
        {
            Console.WriteLine(e);
        }
    }
}