curl --request GET \
  --url https://api.atlas.co/functions/v1/checkout-sessions/{checkout_session_id} \
  --header 'Authorization: Bearer <token>'

{
  "id": "<string>",
  "object": "checkout.session",
  "mode": "<string>",
  "status": "<string>",
  "url": "<string>",
  "customer": "<string>",
  "customer_email": "<string>",
  "payment_status": "<string>",
  "amount_total": 123,
  "currency": "<string>",
  "line_items": {
    "object": "list",
    "data": [
      {
        "price": "<string>",
        "quantity": 123,
        "amount_total": 123
      }
    ]
  },
  "subscription": "<string>",
  "success_url": "<string>",
  "cancel_url": "<string>",
  "expires_at": 123,
  "metadata": {},
  "created": 123
}