curl --request GET \
  --url https://api.example.com/v1/voiceai/analytics/calls \
  --header 'x-api-key: <api-key>'

{
  "metrics": [
    {
      "dt": 123,
      "count": 0,
      "cost": 0,
      "average_cost": 0,
      "llm_cost": 0,
      "average_llm_cost": 0,
      "duration": 0,
      "average_duration": 0
    }
  ],
  "count": 0,
  "cost": 0,
  "average_cost": 0,
  "llm_cost": 0,
  "average_llm_cost": 0,
  "duration": 0,
  "average_duration": 0
}