Only Administrators are allowed to add new users. 

1) To accomplish this, navigate to the Settings and click the Users & Groups tab, followed by the Users sub-tab.

2) Click New User.

3) You will be prompted to add information for the new user:

Note: If your Portal or Style Guide is listed as Public, it will not be listed in the drop-down. Because it is listed portal anyone with the link would have access to this already. 

4) Click on Create New User to finalize the process. 

The new user will receive an email with a link that will grant them access to your Canto account.