Obter um item de assinatura

{
  "id": "si_yRZaVkzMTxmmKp7q",
  "object": "subscription_item",
  "aggregate_usage": "sum",
  "amount_discount": 0,
  "amount_subtotal": 20000,
  "amount_tax": 0,
  "amount_total": 20000,
  "created_at": "2026-05-19T18:00:00Z",
  "currency": "brl",
  "discount": null,
  "metadata": {},
  "position": 1,
  "price": "price_51Kx42mRFxy89i7u",
  "price_data": null,
  "product": "prod_HHFZwqE9F4ESNYWL",
  "quantity": 2,
  "recurring": {
    "interval": "month",
    "interval_count": 1
  },
  "subscription": "sub_S2RCaig5eFnjgyt4",
  "unit_amount": 10000,
  "updated_at": null,
  "usage_period_end": null,
  "usage_period_start": null,
  "usage_type": "licensed"
}

{
  "error": {
    "code": "authentication_failed",
    "message": "Invalid API Key provided: ch_live_***************************************9f2c",
    "type": "authentication_error"
  }
}

{
  "error": {
    "code": "resource_missing",
    "message": "Subscription item not found.",
    "param": "id",
    "type": "invalid_request_error"
  }
}