Enable Two Factor Authentication 

If you have multiple Apple devices, you need to make sure you’re using two-factor authentication. With this, Apple will always require you to confirm that you’re logging in to your Apple Account (Apple ID) by sending a message to your other Apple devices or sending a text message to your phone number.

To use two-factor authentication on your iPhone, you need to follow these steps:

1. Open the Settings app.
2. Tap on your Apple Account (Apple ID) at the top of the settings page.
3. Tap on Sign-In & Security.
4. Under Security, tap on Two Factor Authentication.
5. Tap on Turn On Two Factor Authentication.
6. Tap on Continue and follow the instructions on your screen.

You can also add a hardware security key to your Apple Account if you want even more protection against potential hackers.