When a call comes, flip the phone (regardless of the orientation of the phone screen) to turn off the incoming call sound and vibration.
Note: Flip again will not unmute.
Setting method
realme UI 7.0 & 6.0: Settings > Accessibility & convenience > Gestures & motions > Flip to mute incoming calls
realme UI 5.0 & 4.0 & 3.0: Settings > System / Additional settings > Gestures & motions > Flip to mute incoming calls
realme UI 2.0 & 1.0: Settings > Convenience tools > Gestures & motions > Flip to mute incoming calls
realme UI R & Go & S & T & U Edition: Settings > Smart controls > Smart motion > Turn on Mute incoming calls