You can add additional TitanFile licenses to your subscription in the Billing area of your account.
To access the Billing area, click on Options > Billing.
Then, click the Add Licenses button.
On the next page, click the "-" or "+" buttons to choose the number of licenses you wish to add.
Underneath, it will show you a summary of the changes to your account.
After you've reviewed the changes, click the Confirm button.
Click Yes in the popup that appears.
You should receive a notification indicating that your subscription has been successfully updated and your new number of available licenses will show up in the Subscription Info area.