curl --request GET \
  --url https://sitegpt.ai/api/v2/billing/subscription \
  --header 'Authorization: Bearer <token>'

{
  "ok": true,
  "data": {
    "billing": {
      "id": "billing-id",
      "name": "Example billing",
      "createdAt": "2026-05-13T00:00:00.000Z"
    }
  },
  "meta": {
    "requestId": "request-id"
  }
}