When sharing Tiktok URLs via the app, the autogenerated https://vm.tiktok.com/xxxx/ url contains information about the user who shared it.
When opening these links in a mobile browser, it tells the viewer who generated that shared link.
Using this resource, you'll get a clean URL that does not contain the tracing information.
Fetch the URL with ?url=https://vm.tiktok.com/xxxx/