未定义的索引：将Stripe付款集成到网站PHP时的条带标记

Question

我一直在尝试按照条带文档中提供的说明将Stripe集成到我的网站中。但是，运行时会出现以下错误。

注意：未定义的索引：stripeToken

致命错误：未捕获的异常＆＃39; Stripe \ Error \ InvalidRequest＆＃39;有消息＆＃39;必须提供来源或客户。＆＃39;

require_once('vendor/autoload.php');
\Stripe\Stripe::setApiKey("sk_test_xxxxxxxxxxxxxx");
$token = $_POST['stripeToken'];

// Charge the user's card:
$charge = \Stripe\Charge::create(array(
"amount" => 1000,
"currency" => "usd",
"description" => "Example charge",
"source" => $token,
)); 


<form action="shop.php" method="POST">
<script
 src="https://checkout.stripe.com/checkout.js" class="stripe-button"
 data-key="pk_test_xxxxxxxxxxxxx"
 data-amount="1000"
 data-name="Example"
 data-description="Widget"
 data-image="https://stripe.com/img/documentation/checkout/marketplace.png"
 data-locale="auto">
</script>
</form>

密钥已更改。谢谢你的帮助。