Issues a fresh checkout for an order, for when the checkout the payment form was loaded with has expired, or the customer needs another try. See Host a checkout on your website.

• Use it on a draft, pending, failed or rejected order that has no successful payment. Any order on your profile qualifies, wherever it was created.
• The body is optional. Send redirect_success_url or redirect_failed_url only to change them. After the change, the order must hold both.
• Renewing doesn't change the order's status and sends no webhook. Every call issues a new checkout: use the newest one.
• Renewing a failed order holds (pre-authorises) your profile's default initial amount, to check the card.
• If the gateway fails, you still get 201. checkout.result says why and the other checkout fields are null. Renew again.

The gateway decides how long a checkout lasts. Renew when the payment form reports that it has expired.