PHP 楽天ショッピングの注文情報を取得するには？

<?php
$serviceSecret = '';
$licenseKey    = '';

$header = array(
  'Authorization: ESA '.base64_encode($serviceSecret.':'.$licenseKey),
  'Content-Type: application/json; charset=utf-8',
);

$post = array(
  'dateType' => '1', // 1:注文日
  'startDatetime' => '2023-11-18T23:00:00+0900',
  'endDatetime'   => '2023-11-19T23:59:59+0900',
  'PaginationRequestModel' => array(
      'requestRecordsAmount' => 100, // 100件取得
      'requestPage' => 1, // 1ページ目
      'SortModelList' => array(
        array(
          'sortColumn'    => 1, // 1: 注文日時
          'sortDirection' => 1, // 1: 昇順（小さい順、古い順）
        )
      )
    )
  );
$post = json_encode($post);

$request = array(
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_POST           => true,
  CURLOPT_POSTFIELDS     => $post,
  CURLOPT_HTTPHEADER     => $header,
);

$curl = curl_init('https://api.rms.rakuten.co.jp/es/2.0/order/searchOrder/');
curl_setopt_array($curl,$request);
$json = curl_exec($curl);
curl_close($curl);
$json = json_decode($json);
mb_convert_variables('eucJP-win','UTF-8',$json);
var_dump($json);