SmarterTrack includes the link to the Management Interface as part of the user menu at the top of the portal pages (see below). This menu option is automatically removed from the menu for users without any employee roles. The button shown in your screenshot was probably added using some of SmarterTrack's customization features, such as a custom Main Portal Announcement and Custom CSS Style Overrides. I would recommend checking your custom styles and announcements to see if that is where this button is coming from.