问总是从微软翻译器得到401

EN

    private static readonly string subscriptionKey = "<KEY>";
    private static readonly string endpoint = "https://api-eur.cognitive.microsofttranslator.com/";

    static Program()
    {
        if (null == subscriptionKey)
        {
            throw new Exception("Please set/export the environment variable: " + key_var);
        }
        if (null == endpoint)
        {
            throw new Exception("Please set/export the environment variable: " + endpoint_var);
        }
    }
    static async Task Main(string[] args)
    {
        string route = "/translate?api-version=3.0&to=de&to=it&to=ja&to=th";
        Console.Write("Type the phrase you'd like to translate? ");
        string textToTranslate = Console.ReadLine();
        await TranslateTextRequest(subscriptionKey, endpoint, route, textToTranslate);
        Console.WriteLine("Press any key to continue.");
        Console.ReadKey();
    }
  
    static public async Task TranslateTextRequest(string subscriptionKey, string endpoint, string route, string inputText)
    {
        object[] body = new object[] { new { Text = inputText } };
        var requestBody = JsonConvert.SerializeObject(body);

        using (var client = new HttpClient())
        using (var request = new HttpRequestMessage())
        {
            request.Method = HttpMethod.Post;
            // Construct the URI and add headers.
            request.RequestUri = new Uri(endpoint + route);
            request.Content = new StringContent(requestBody, Encoding.UTF8, "application/json");
            //request.Headers.Add("Ocp-Apim-Subscription-Key", subscriptionKey);
            request.Headers.Add("Ocp-Apim-Subscription-Region", subscriptionKey);

            // Send the request and get response.
            HttpResponseMessage response = await client.SendAsync(request).ConfigureAwait(false);
            // Read response as a string.
            string result = await response.Content.ReadAsStringAsync();
            // Deserialize the response using the classes created earlier.
            TranslationResult[] deserializedOutput = JsonConvert.DeserializeObject<TranslationResult[]>(result);
            // Iterate over the deserialized results.
            foreach (TranslationResult o in deserializedOutput)
            {
                // Print the detected input language and confidence score.
                Console.WriteLine("Detected input language: {0}\nConfidence score: {1}\n", o.DetectedLanguage.Language, o.DetectedLanguage.Score);
                // Iterate over the results and print each translation.
                foreach (Translation t in o.Translations)
                {
                    Console.WriteLine("Translated to {0}: {1}", t.To, t.Text);
                }
            }
        }