curl --request GET \
  --url https://supertoneapi.com/v1/usage \
  --header 'x-sup-api-key: <api-key>'

{
  "data": [
    {
      "starting_at": "2024-01-01T00:00:00+09:00",
      "ending_at": "2024-01-01T01:00:00+09:00",
      "results": [
        {
          "voice_id": "<string>",
          "voice_name": "<string>",
          "api_key": "<string>",
          "minutes_used": 123
        }
      ]
    }
  ],
  "next_page_token": "<string>",
  "total": 123
}