Go to Accounts > Enquiry > Active Users

1. Current Login/user

Your current login/user (1) will be in a blue font when not selected/highlighted

It is suggested NOT to Clear this station/user - Exit as per this article

2. Clear Station

Make sure the user is NOT in the middle of a current process before clearing
You will leave locked files in the background and possibly cause corruptions

3. Block all users

If ticked - all other users will not be able to be logged in.