Authorization: Bearer ********************curl --location 'https://witlark.com/kling/v1/videos/video-extend' \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '{
"video_id": "string",
"prompt": "string",
"negative_prompt": "string",
"cfg_scale": 0,
"callback_url": "string"
}'{}