tiktok downloader is a tool to download video from tiktok with watermark or without watermark. There are two features that is, mass download (by username/urls) and single download (by url).
I think it's from reverse engineering process. But instead of spending time for that, you should use this one to save time https://apify.com/novi/fast-tiktok-api
I still wonder why people are fine useful tiktok api like that? https://api16-normal-c-useast1a.tiktokv.com