Extend a Kling video

curl https://api.cometapi.com/kling/v1/videos/video-extend \
  -H "Authorization: Bearer $COMETAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{
      "task_id": "<parent_task_id>",
      "video_id": "<video_id>",
      "prompt": "Continue with the same calm morning atmosphere",
      "cfg_scale": 0.5
    }'

{
  "code": 123,
  "message": "<string>",
  "request_id": "<string>",
  "data": {
    "task_id": "<string>",
    "task_status": "<string>",
    "task_status_msg": "<string>",
    "task_info": {
      "parent_video": {
        "id": "<string>",
        "url": "<string>",
        "duration": "<string>"
      }
    },
    "task_result": {
      "videos": [
        {
          "id": "<string>",
          "url": "<string>",
          "duration": "<string>"
        }
      ]
    },
    "created_at": 123,
    "updated_at": 123
  }
}