After computer mobile phone games, after installation, they always say that they need to send text messages to activate and ask for money.

This has nothing to do with whether you downloaded it from the computer or not. It's the game itself. Some games are free, and some games need to be paid when playing. Generally, these games have built-in fee deduction software. If you can't call, don't call, or the phone bill will be deducted for no reason.