Why does Tik Tok Store app receive information? Tik Tok account can receive information.

Because your account number in Shadian is the same as your account number in Tik Tok, you receive the same information.

Why is there only one pop-up window in Tik Tok for my private message?

This may be because your Tik Tok is not running in the background. If your mobile phone doesn't run Tik Tok, you can't see the private messages sent by others, and you can only see them after you re-enter Tik Tok.