To lock Yoti Password Manager just click on the 
icon in the extension. Yoti Password Manager will lock itself after a certain amount of browser inactivity. You can choose what length of time your browser has to be inactive for before Password Manager locks. If you want to know how to do this, please click here.
To unlock Yoti Password Manager you need to have your phone at hand. To unlock, open the extension and click Unlock. Then approve the unlock request on your phone.