Invoice OCR Recognition API Introduction Source Code var client = new HttpClient(); var request = new HttpRequestMessage(HttpMethod.Post, "https://netocr.com/api/v2/recogInvoiveBase64.do"); var content = new MultipartFormDataContent(); content.Add(new StringContent("/9j"), "img"); content.Add(new StringContent("M***********g"), "key"); content.Add(new StringContent("3***********6"), "secret"); content.Add(new StringContent("20090"), "typeId"); content.Add(new StringContent("json"), "format"); request.Content = content; var response = await client.SendAsync(request); response.EnsureSuccessStatusCode(); Console.WriteLine(await response.Content.ReadAsStringAsync());