For security reasons, only your Partner or Sub Users can be designated as a Backup Contact.
From the “Manage Collaborator” page, select the user you’d like to become your Backup Contact. In the “Add a Collaborator” section, click the checkbox for “Make this user a Backup Contact,” and proceed to set the Inactivity Notification Period.
Once the Inactivity Period has passed, you will be sent a courtesy email to tell you that your pre-chosen inactivity period has concluded. If there still has been no log in activity, then the Backup Contact(s) will be contacted.
Your Backup Contact will then be able to access your account based on the permissions you chose.