TalkBack may be called Voice Assistant on some devices.
From a Home screen, swipe up to access all apps.
Navigate: Settings > Accessibility.
Tap 'TalkBack' or 'Vision'.
Tap the TalkBack switch to turn on or off .
When turned on, use two-finger swipe to navigate/scroll and double tap to select.
If Google Voice™ is turned on, you can ask Google Assistant to turn off TalkBack.
If prompted, tap 'OK' or 'TURN ON'.
To access lock screen with TalkBack on, tap the lock on the front screen then double tap to enter lock code.