To screen record on an LG, you'll need to swipe down from the top of your screen to access the notification panel. From there, you can long press the "Screen Record" button, which looks like a little video camera. This will open up the screen recording settings, where you can choose the quality and sound options.
Once you've got everything set up, just tap the "Start" button to begin recording. You can then navigate to the screen you want to capture and start recording your favorite game or video. It's that simple!