They are not the same person, they just have the same name.

Douyin (English name: TikTok) is a short video sharing software launched by ByteDance. It was launched on May 25, 2016. It is a music short video community platform for all ages. Douyin uses artificial intelligence technology to create a variety of gameplay for users. Users can use this software to select songs, shoot short music videos, form their own works and share them with users on the platform.