curl --request GET \
  --url 'https://api.example.com/api/v1/agency/billing/{agency_id}/billing_plan/list?api_key='

{
  "data": {
    "items": [
      {
        "name": "<string>",
        "description": "<string>",
        "bots_count": 123,
        "queries_count": 123,
        "words_count": 123,
        "voice_seconds": 123,
        "premium_support": true,
        "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "default_plan": false,
        "remove_branding": false,
        "advanced_intents": false,
        "auto_intents": false,
        "billing_plan_group": "<string>",
        "credits": {},
        "attributes": {},
        "agency_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "user_count": 0,
        "plan_lookup_key": "<string>"
      }
    ],
    "total": 1,
    "page": 2,
    "size": 2,
    "pages": 1,
    "previous_page": 123,
    "next_page": 123
  },
  "message": "",
  "meta": {}
}