log off
phrasal verblog off/out (of something)  
- (computing) to perform the actions that allow you to finish using a computer system, application or online account- Log off before switching the computer off.
- Make sure you log out of your account on public computers.
 
log somebody  off/out (of something)  
- (computing) to cause somebody to finish using a computer system, application or online account- The system will automatically log you off after 30 minutes.