How to get section id for apple news?

Hello.


I am trying to get a list of section id under my channel. I am following the Apple News API documentation (https://developer.apple.com/documentation/apple_news/list_all_sections) . But I am getting 401-unauthorized error? I am calculating the signature the same way as I do for article creation. Following is my code:


String method = String.valueOf(HttpMethod.GET);
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
outputStream.write(method.getBytes(MESS_ENCODING));
outputStream.write(url.getBytes(MESS_ENCODING));
outputStream.write(appleDate.getBytes(MESS_ENCODING));


byte[] base64EncodedMac = Base64.getEncoder().encode(hmacUtils.hmac(outputStream.toByteArray()));
String signature = new String(base64EncodedMac);
String authorization = String.format(HEADER_FORMAT, api_key_id, signature, appleDate);

exchange.getOut().setHeader(AUTH_HEADER, authorization);
exchange.getOut().setHeader(Exchange.HTTP_METHOD, method);

Is there any other way to get section ID?


Tahseen