curl --request GET \
  --url 'https://aireiter.com/api/openapi/balance' \
  --header 'Authorization: Bearer <token>'

{
  "statusCode": 200,
  "message": "",
  "data": {
    "credits": 500,
    "free_quotas": [
      {
        "model_key": "nano_banana_v2",
        "total": 10,
        "used": 3,
        "remaining": 7
      }
    ]
  },
  "ok": true
}