Extend unlock is the new name of Smart lock feature provided by Google Android. Extend Unlock keeps this device unlocked when it's with you.
Extend Unlock can recognize when: You're holding this device/ You're near home or another trusted place/Your watch or another trusted device is nearby.
Setting Path:
realme UI 7.0 & 6.0 & 5.0: Settings > Security and Privacy > More Security and Privacy > Extend unlock
realme UI 4.0 & 3.0: Settings > Password & security > System security > Smart lock
realme UI 2.0 & 1.0: Settings > Fingerprint, face & password > Smart lock
realme UI U Edition: Settings > Security & privacy > More security and privacy > Extend Unlock
realme UI R & S & T & Go Edition: Not supported