List available voices

{
  "voices": [
    {
      "voice_id": "21m00Tcm4TlvDq8ikWAM",
      "name": "Rachel",
      "description": "A clear, professional voice perfect for legal presentations",
      "category": "premade",
      "labels": {
        "accent": "american",
        "age": "young",
        "gender": "female",
        "use_case": "narration"
      },
      "preview_url": "https://api.elevenlabs.io/v1/voices/21m00Tcm4TlvDq8ikWAM/preview",
      "available_for_tiers": [
        "free",
        "starter",
        "creator",
        "pro"
      ]
    }
  ],
  "next_page_token": "eyJ2b2ljZV9pZCI6IjIxbTAwVGNtNFRsdkRxOGlrV0FNIn0",
  "total_count": 142
}