Click on the Users tab (the settings area) to manage users for your account.

To add a new user, press ADD NEW USER at the top right of the screen.

Then, specify an email address of the person that you would like to add. 

You must also select a role for the new user. You can choose from such options as UserManager, and Administrator.

Once both fields are completed, press ADD USER to confirm or Close to dismiss.

Invited users will receive an email with further instructions and links to set up their password.