Settings Path:
realme UI 2.0 & above versions do not support automatically hiding the virtual buttons, but you can choose gesture navigation to hide virtual buttons.
realme UI 1.0: Settings > Convenience Tools > Navigation buttons > Virtual buttons > Auto hide virtual buttons
realme UI Go & T & R & U & S Edition: Not support automatically hiding the virtual buttons, but you can choose gesture navigation to hide virtual buttons.
How to Set Gesture Navigation?
Settings Path:
realme UI 6.0: Settings > System & updates > System navigation > Buttons.
realme UI 5.0 & 4.0 & 3.0: Settings > System/Additional settings > System navigation > Gesture
realme UI 2.0: Settings > Convenience Tools > Navigation > Swipe gestures from both side
realme UI R & Go & T & S & U Edition: Settings > System > Gestures > System navigation/Navigation mode > Gesture
Related Articles:
How to set virtual or navigation buttons
How to change the layout of virtual buttons