我想通過 Billing REST Api 獲得 Azure RateCard Json 響應。為此，我在 Eclipse 中使用以下代碼：import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import com.fasterxml.jackson.core.JsonFactory;import com.fasterxml.jackson.core.JsonParser;import com.fasterxml.jackson.core.JsonToken;public class RateCardRest {public static String getAccessToken(String tenantId, String clientId, String clientSecret)        throws MalformedURLException, IOException {    String endpoint = String.format("https://login.microsoftonline.com/%s/oauth2/token", tenantId);    String postBody = String.format("grant_type=client_credentials&client_id=%s&client_secret=%s&resource=%s",            clientId, clientSecret, "https://management.azure.com/");    HttpURLConnection conn = (HttpURLConnection) new URL(endpoint).openConnection();    conn.setRequestMethod("POST");    conn.addRequestProperty("Content-Type", "application/x-www-form-urlencoded");    conn.setDoOutput(true);    conn.getOutputStream().write(postBody.getBytes());    conn.connect();//      If you want to see the response content, please use the commented code below.//      BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));//      StringBuilder builder = new StringBuilder();//      String line = null;//      while ((line = reader.readLine()) != null) {//          builder.append(line);//      }//      reader.close();//      System.out.println(builder.toString());//      The output for access token is         String name = parser.getCurrentName();        if ("access_token".equals(name)) {            parser.nextToken();            accessToken = parser.getText();        }    }    return accessToken;}當我搜索 URL 時，我收到以下消息：AADSTS900561：端點只接受 POST、OPTIONS 請求。收到一個 GET 請求。