Setting Path:
realme UI 3.0 & above versions: Settings > Security & privacy/Privacy > Hide Apps > Set Access Code/Change access code.
realme UI 2.0: Settings > Passcode & biometrics > Privacy Password > Hide Apps > Settings > Change Access Number.
realme UI 1.0: Not supported resetting access code
realme R & Go & T & S & U Edition: Not supported Hide Apps