When the screen is off, draw || with two fingers on the screen at the same time to pause or play tracks, and draw < or > to switch tracks.
Setting method:
realme UI 7.0 & 6.0: Settings > Accessibility & convenience > Gestures & motions > Screen-off gestures > Music control
realme UI 5.0 & 4.0 & 3.0: Settings > System/Additional settings > Gestures & motions > Screen-off gestures > Music control
realme UI 2.0 & 1.0: Settings > Convenience tools > Gestures & motions > Screen-off gestures > Music control
realme UI R & Go & T & S & U Edition: Not supported