After you log into your Account, go to the "Profile" tab. Under the user section, click the "Add" button. A new row will appear in the "Users" table. Enter a name and email address, and click on "Save" at the very bottom of the page.
Before a new user logs in for the first time, the password needs to be reset in the Account: https://cerebrohq.com/en/ac-reset-password
If you need to delete an old account, log in as the new user and go to the "Profile" tab. In the user table, click "Delete" in the user row and click "Save" at the bottom of the page.