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

{
  "items": [
    {
      "voice_id": "<string>",
      "name": "<string>",
      "description": "<string>",
      "age": "<string>",
      "gender": "<string>",
      "use_case": "<string>",
      "language": "<string>",
      "styles": "<string>",
      "models": "<string>",
      "samples": [
        {
          "language": "<string>",
          "style": "<string>",
          "model": "<string>",
          "url": "<string>"
        }
      ],
      "thumbnail_image_url": "<string>"
    }
  ],
  "total": 150,
  "nextPageToken": "some_opaque_token_string_representing_last_id"
}