Hello, Yizzy. As I know, TikTok is currently ONLY available on some countries across Europe, such as the United Kingdom, France and Germany. It’s compatible with Google TV and some Android TV OS devices produced by Sony, Hisense, TCL, Skyworth, Sharp, Phillips, Xiaomi, Panasonic and Toshiba. There's also another version of TikTok for Samsung TVs that don't run Android TV (
see more on TikTok Official News). Feel free to download it on Google Play and watch TikTok on TV.
As for how to put TikTok on your TV and set it up, you can see the instructions as follows:
Open Google Play and search TikTok on the searching bar;
Click, install the app and open it;
Log in or just browse the content immediately as a visitor.
Hope this helps.