Android 15's new "Private Space" feature allows you to lock away specific apps on your device, adding an extra layer of security and privacy. This virtual vault can be accessed by scrolling to the app drawer, tapping the padlock icon, and authenticating using a biometric method or PIN. You can install and uninstall apps within Private Space, but notifications will only be received when it's unlocked.

Source: https://www.theverge.com/24279464/private-space-android-15-pixel-how-to