Duo Security Admin API 用户请求在 Java 中使用失败

问：

我正在使用 Duo Security Admin API。但是当我使用以下代码调用 api 时，它显示：

Get Users request failed with HTTP (response code: 401)

这是我的 java 代码：

    void users(){

    // Duo Admin API credentials and API hostname
    String integrationKey = "DI7ABPU9TUJQO14RET9Q";
    String secretKey = "YzDs7ZeQGMllravxDQxcn4jNAwyqF42P1XBDdGd2";
    String apiHostname = "api-d221a358.duosecurity.com";

    try {

        String usersUrl = "https://" + apiHostname + "/admin/v1/users";
        // Create URL object
        URL url = new URL(usersUrl);

        // Open a connection to the URL
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();

        // Set request method to GET
        connection.setRequestMethod("GET");

        // Set request headers
        connection.setRequestProperty("Authorization", "Basic " + getBase64Credentials(integrationKey, secretKey));
        connection.setRequestProperty("Date", OffsetDateTime.now().format(DateTimeFormatter.RFC_1123_DATE_TIME));
        connection.setRequestProperty("Content-Type", "application/json");

        // Get the HTTP response code
        int responseCode = connection.getResponseCode();

        if (responseCode == HttpURLConnection.HTTP_OK) {
            // Read and print the response (list of users)
            try (BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()))) {
                String inputLine;
                StringBuilder response = new StringBuilder();

                while ((inputLine = in.readLine()) != null) {
                    response.append(inputLine);
                }

                System.out.println("List of Users: " + response.toString());
            }
        } else {
            System.out.println("Get Users request failed with HTTP response code: " + responseCode);
        }

        // Close the connection
        connection.disconnect();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

// Encode credentials as Base64
private static String getBase64Credentials(String integrationKey, String secretKey) {
    String credentials = integrationKey + ":" + secretKey;
    return java.util.Base64.getEncoder().encodeToString(credentials.getBytes());
}

我的代码犯了什么错误？ 调用 Duo Security Admin API 的方法是否正确？

请帮帮我..