How is it work?

Example:
https://www.tiktok.com/@ponciklendin/video/6786553850611469573
or
https://m.tiktok.com/v/6786553850611469573.html
or
https://www.iesdouyin.com/share/video/6800921931982834951/?region=CN&mid=6800902232562060046&u_code=0&titleType=title