To add admins to your dashboard please go to Attendees > Admin Settings > + Add Admin. You will need the person's first and last name and their email. Once added, the person will receive an automated email from Whova notifying them that they have been added. If the admin email that is added is a new account, a temporary password will be sent as well.
If you or your colleague do not receive an email with access instruction after being added in as an admin please check your spam folder. If it is also not in your spam folder please contact Support@whova.com.