This tool is for VSys Anywhere users only, and lets those users who currently know their password update it. To allow users to reset their passwords, use the Password reset action link.
Depending on how VSys Anywhere is configured, i.e. if you can login in using either of a VSys Live account or a VSys Security account, you may be prompted for Login account: this is the account whose password you're looking to change.
In the tool profile for this tool, you can have VSys default to showing the VSys Live login where both are possible for a given user.