Hello @shivam1
You can download it using this api - (if you are using paginated reports in quicksight)
This post has some insights too - Quicksight API (export the analysis into CSV format) - #2 by Shahid_Muhammad
Youtube video - https://www.youtube.com/watch?v=pC9mXpy7208
FYI, i believe it is an add-on to the Paginated Reports in Quicksight. There is a cost associated with this reports when you enable it so please make sure to check the pricing too.
Thank you,
Shravya