The feature to create additional logins in a SideFX license account is only available for Education and Commercial users.
Please email the support team (support@sidefx.com) to be given the ability to Admin Users.

1. Log into your SideFX account at www.sidefx.com/services.
   
2. Navigate to the License Manager section
   
3. Click on the Manage Logins link
   

Options:

Allow License Management
The user may install licenses locally to a workstation or server.

Allow Login-Based Licensing
Give the user access to using SideFX as the license server.

Can see billing
View quotes and invoices for the account.

Allow creation of other account logins
Administrative access to create logins for the account.

If you want users to only use SideFX as the license server then ensure Allow License Management is toggled off and Allow Login-Based Licensing is toggled on.
If Allow License Management is left toggled on, the corresponding user will be able to install a license directly onto their machine, removing it from the license pool available to other users.