Better idea:

Force ByteDance to take on an American partner in operating TikTok in the US. All data must be handled on servers hosted by this partner purely in the United States, for a "nominal" fee. ByteDance must open up its source code to inspection by this partner and any US government agency that wants to see it, at will, no questions asked. The US government may halt the use of their service at any time for any reason, with or without an appeals process. Ideally, Canada, Australia, New Zealand, the UK, and EU take up the same regime.

This is basically the bar set by the CCP for Westerners to operate within PRC; turnabout is fair play.