A Force Check In of a Supervisor floating license is available to the Primary Contact of a license account and any user with Manage Users permission.
Log into https://my.snowdenonline.com.au using your account.
On the MY LICENSES page, you will see the products that you have access to. From this screen click on the View Seats button.
On the right hand side of an occupied seat is the "Force Check In" button
Clicking on this will check in the license and make it available for check out.