Adding existing users to your new Kablink® Teaming site was part of the installation process, as described in Adding Teaming Users from Your LDAP Directory
in Basic Installation
in the Kablink Teaming 2.0 Installation Guide.
However, as time passes, you need to add new users. Depending on the needs of your Teaming site, you might want to allow people to access the site even if they do not have Teaming user accounts in the Teaming system. You might even want to allow such people to create their own Teaming user accounts without you as an administrator doing it for them.