To make an LED light blink on receiving any notification on the iPhone which is present at the back of the iPhone. It will start blinking on calls, text messages, or other notifications. The LED light blinks to receive notifications which help user to easily notify.

Note: Enable the LED light has an impact on battery life, as using the LED flash for alerts may consume more power.

Following are the steps to enable the flashlight:

1. Open the Settings on your iPhone.
2. Go to the Accessibility –> Audio/Visual –> LED Flash for Alerts –> Enable.

Please refer to the following pictures to enable: