Make sure your Google Apps domain administrator gives you the right privileges. See the "Grant permissions to view users in domain" section on the Configuring Google Apps page.
Once you've completed the above steps, you will be ready to load user accounts from Google. To do that with Primalogik, click on the Settings and then go to Users and click on Import at the top right of your screen.
Selecting "Import from Google" will allow you to load and select the individuals you want to enable in Primalogik.
For more information about the integration with Google Apps please refer to Configuring integration with Google Apps.