LG K20 Plus User Manual page 26

Touching and holding
Touch and hold for several seconds to display a menu with available
options.
Double-tapping
Tap twice quickly to zoom in or out on a web page or map.
Dragging
Touch and hold an item, such as an app or widget, then move your
finger to another location in a controlled motion. You can use this
gesture to move an item.
Basic Functions 25