When you discover that your phone is missing, it is best to change your password as soon as possible.
Changing your password
Note: You can access this site even through a borrowed phone, just make sure you don't automatically save your new password in their password manager.
Log in with your credentials.
Note: Your account will now be logged out on your phone and won't be able to be used to open your lock.
fill in your current password once and your new password twice.
press the “change now” button.
Your password is now changed.