Firstly, ensure your device is running Android 14 or higher, then open the Settings app and navigate to Notifications, swiping down to the General section and selecting Flash notifications
You can choose to have the Camera flash to alert you, or you can select a colour and have the screen flash instead
If your phone is running an older version of Android, you can download a third-party app such as Flash Alert & LED Flashlight which will allow you to set flash alerts for incoming calls, SMS messages or app notifications, with options to customise the speed and number of flashes
On Samsung Galaxy devices, you may be able to access the flash notification feature through the Settings app by navigating to Accessibility and selecting the Flash notification option in Advanced settings
