curl --request GET \
  --url https://api.perplexity.ai/async/chat/completions/{request_id} \
  --header 'Authorization: Bearer <token>'

{
  "id": "<string>",
  "model": "<string>",
  "created_at": 123,
  "status": "CREATED",
  "started_at": 123,
  "completed_at": 123,
  "response": {
    "id": "<string>",
    "model": "<string>",
    "created": 123,
    "usage": {
      "prompt_tokens": 123,
      "completion_tokens": 123,
      "total_tokens": 123,
      "search_context_size": "<string>",
      "citation_tokens": 123,
      "num_search_queries": 123,
      "reasoning_tokens": 123
    },
    "object": "chat.completion",
    "choices": [
      {
        "index": 123,
        "message": {
          "content": "<string>",
          "role": "system"
        },
        "finish_reason": "stop"
      }
    ],
    "search_results": [
      {
        "title": "<string>",
        "url": "<string>",
        "date": "2023-12-25"
      }
    ],
    "videos": [
      {
        "url": "<string>",
        "thumbnail_url": "<string>",
        "thumbnail_width": 123,
        "thumbnail_height": 123,
        "duration": 123
      }
    ]
  },
  "failed_at": 123,
  "error_message": "<string>"
}