Use The Touchscreen - LG X POWER User Manual

Your screen remains blank while your phone is off (unless the battery is charging).
Tip: The KnockON feature allows you to double-tap the screen to easily turn it on or off.

Use the Touchscreen

Your phone's touchscreen lets you control actions through a variety of touch gestures.
Tap
When you want to type using the onscreen keyboard, select items onscreen, such as application and
settings icons, or press onscreen buttons by simply tapping or touching them with your finger.
Getting Started Set Up Your Phone 9