curl --request POST \
  --url https://api.pocketsflow.com/checkout/sessions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "productId": "<string>",
  "successUrl": "<string>",
  "cancelUrl": "<string>",
  "customerEmail": "jsmith@example.com",
  "discountCode": "<string>",
  "metadata": {}
}
'

{
  "id": "<string>",
  "url": "<string>"
}