curl --request GET \
  --url https://api.example.com/v1/voiceai/conversations/{conversation_id}

{
  "agent_id": "<string>",
  "conversation_id": "<string>",
  "status": "<string>",
  "metadata": {
    "start_time_unix_secs": 123,
    "call_duration_secs": 123,
    "phone_call": {}
  },
  "transcript": [],
  "has_audio": false
}