Path:
realme UI 7.0: Settings > Home screen, Lock screen & style > Always-On Display > Seamless clock/Classic clock
realme UI 6.0: Settings > Wallpapers & style > Always-On Display > Seamless clock/Classic clock
realme UI 5.0 & 4.0 & 3.0: Settings > Home screen & Lock screen > Clock style
realme UI 2.0: Not supported
realme UI R & Go & T & U & S Edition: Not supported
Note: Except for realme 14X 5G, only models with OLED screen support AOD.