Squareを使用した決済。メモや商品名を決済に登録したい

phpでSquareを用いた決済の実装を行っています。
まずはサンプルを試しています。ダウンロードしたサンプルはこちら。
https://github.com/square/connect-api-examples/tree/master/connect-examples/v2/php_payment

テストで本番決済できましたが、

Squareの管理画面のお取引に表示される商品が「任意の金額」となっております。
こちらにphpで吐き出した注文IDや商品名などを表示（登録）させたいのですが、
方法がわかりません…

ご存じの方いらっしゃいましたら、ご教示いただけますと幸いです。
以下、コードです。（gitのサンプルほぼそのままですが）

index.php（決済フォームのあるページ）

<?php
require_once ("../../vendor/autoload.php");

use Square\Environment;
// dotenv is used to read from the '.env' file created for credentials
//$dotenv = Dotenv\Dotenv::create(__DIR__);
//$dotenv->load();

// Pulled from the .env file and upper cased e.g. sandbox, production.
$upper_case_environment = strtoupper("production");

?>
<html>
<head>
  <title>My Payment Form</title>
  <!-- link to the SqPaymentForm library -->
  
  <script type="text/javascript" src=
    <?php
        echo "\"";
        echo ("production" === Environment::PRODUCTION)  ?  "https://js.squareup.com/v2/paymentform"
                                            :  "https://js.squareupsandbox.com/v2/paymentform";
        echo "\"";
    ?>
  ></script>
  <script type="text/javascript">
    window.applicationId ="アプリケーションIDをもってきます";
    window.locationId ="ロケーションIDをもってきます";
  </script>

  <!-- link to the local SqPaymentForm initialization -->
  <script type="text/javascript" src="js/sq-payment-form.js"></script>
  <!-- link to the custom styles for SqPaymentForm -->
  <link rel="stylesheet" type="text/css" href="css/sq-payment-form.css">
</head>
<body>
  <!-- Begin Payment Form -->
  <div class="sq-payment-form">
    <!--
      Square's JS will automatically hide these buttons if they are unsupported
      by the current device.
    -->
 
    <div id="sq-ccbox">
      <!--
        You should replace the action attribute of the form with the path of
        the URL you want to POST the nonce to (for example, "/process-card").

        You need to then make a "Charge" request to Square's Payments API with
        this nonce to securely charge the customer.

        Learn more about how to setup the server component of the payment form here:
        https://developer.squareup.com/docs/payments-api/overview
      -->
      <form id="nonce-form" novalidate action="./process-card.php" method="post">
        <input type="hidden" value="12121212" name="order_id">
        <input type="hidden" value="100" name="total_price">
        <div class="sq-field">
          <label class="sq-label">カード番号</label>
          <div id="sq-card-number"></div>
        </div>
        <div class="sq-field-wrapper">
          <div class="sq-field sq-field--in-wrapper">
            <label class="sq-label">ｾｷｭﾘﾃｨｺｰﾄﾞ</label>
            <div id="sq-cvv"></div>
          </div>
          <div class="sq-field sq-field--in-wrapper">
            <label class="sq-label">有効期限</label>
            <div id="sq-expiration-date"></div>
          </div>
          <div class="sq-field sq-field--in-wrapper">
            <label class="sq-label">郵便番号</label>
            <div id="sq-postal-code"></div>
          </div>
        </div>
        <div class="sq-field">
          <button id="sq-creditcard" class="sq-button" onclick="onGetCardNonce(event)">
            100円を支払う
          </button>
        </div>
        <!--
          After a nonce is generated it will be assigned to this hidden input field.
        -->
        <div id="error"></div>
        <input type="hidden" id="card-nonce" name="nonce">
      </form>
    </div>
  </div>
  <!-- End Payment Form -->
</body>
</html>

process-card.php（決済の処理を行うページ）

<?php

// Note this line needs to change if you don't use Composer:
// require('square-php-sdk/autoload.php');
require_once ("../../vendor/autoload.php");

//use Dotenv\Dotenv;
use Square\Models\Money;
use Square\Models\CreatePaymentRequest;
use Square\Exceptions\ApiException;
use Square\SquareClient;

//追加 前ページからIDと金額を取得。※現在は前ページはべた書き
$order_id = $_POST["order_id"];
$total_price = $_POST["total_price"];

// Pulled from the .env file and upper cased e.g. SANDBOX, PRODUCTION.
$upper_case_environment = strtoupper("production");

// The access token to use in all Connect API requests.
// Set your environment as *sandbox* if you're just testing things out.
$access_token =  "アクセストークンをもってくる";    

// Initialize the Square client.
$client = new SquareClient([
  'accessToken' => $access_token,  
  'environment' => "production"
]);

// Helps ensure this code has been reached via form submission
if ($_SERVER['REQUEST_METHOD'] != 'POST') {
  error_log('Received a non-POST request');
  echo 'Request not allowed';
  http_response_code(405);
  return;
}

// Fail if the card form didn't send a value for `nonce` to the server
$nonce = $_POST['nonce'];
if (is_null($nonce)) {
  echo 'Invalid card data';
  http_response_code(422);
  return;
}

$payments_api = $client->getPaymentsApi();

// To learn more about splitting payments with additional recipients,
// see the Payments API documentation on our [developer site]
// (https://developer.squareup.com/docs/payments-api/overview).

$money = new Money();
  // Monetary amounts are specified in the smallest unit of the applicable currency.
  // This amount is in cents. It's also hard-coded for $1.00, which isn't very useful.
$money->setAmount($total_price);
$money->setCurrency('JPY');
//$money->setNote('test');

  // Every payment you process with the SDK must have a unique idempotency key.
  // If you're unsure whether a particular payment succeeded, you can reattempt
  // it with the same idempotency key without worrying about double charging
  // the buyer.
$create_payment_request = new CreatePaymentRequest($nonce, uniqid(), $money);

// The SDK throws an exception if a Connect endpoint responds with anything besides
// a 200-level HTTP code. This block catches any exceptions that occur from the request.
try {
  $response = $payments_api->createPayment($create_payment_request);
  // If there was an error with the request we will
  // print them to the browser screen here
  if ($response->isError()) {
    echo 'Api response has Errors';
    $errors = $response->getErrors();
    echo '<ul>';
    foreach ($errors as $error) {
        echo '<li>❌ ' . $error->getDetail() . '</li>';
    }
    echo '</ul>';
    exit();
  }
  echo '<pre>';
 
//決済IDの取得
  $resp_arr = $response->getBody();
  $resp_dec = json_decode($resp_arr, true);
  $pmtid = $resp_dec["payment"] ["id"];
  print($pmtid);
  
  echo '</pre>';
} catch (ApiException $e) {
  echo 'Caught exception!<br/>';
  echo('<strong>Response body:</strong><br/>');
  echo '<pre>'; var_dump($e->getResponseBody()); echo '</pre>';
  echo '<br/><strong>Context:</strong><br/>';
  echo '<pre>'; var_dump($e->getContext()); echo '</pre>';
  
  exit();
}