How exactly does he plan to ban it? He may try to take it off app stores, but at least on android, users can just install an apk.
For entities with a US presence, the threat of prosecution usually does the trick (see https://codeisfreespeech.com/)
all five of them. Remove it from app stores, make it illegal to carry and it's toast. If no one in your circle has that app, no point on installing it.
The app stores can fight any such order longer than Trump can remain president.
There is nothing he can do.
>Trump said he could use emergency economic powers or an executive order to ban TikTok in the United States.
He's not wrong.