Authorization: Bearer ********************curl --location --request POST '/kling/v1/videos/video-extend' \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data-raw '{\r\n \"video_id\": \"828006748715380777\",\r\n \"prompt\": \"Extend animation effect\",\r\n \"negative_prompt\": \"\",\r\n \"cfg_scale\": 0.5,\r\n \"callback_url\": \"\"\r\n}'{}