Tap twice to quickly turn off the screen without pressing the power button.
The method to tap twice to turn off the screen on Asus Zenfone 4 Max ZC520KL is as follows:
Step 1: Go to ZenMotion settings.
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Access ZenMotion settings
Step 2: Access touch gestures.
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Access touch gestures
Step 3: Activate the feature.
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Activate the function
That completes your setup process. Wishing you all success.