How Can an End-User Check the Status of a Ticket?

How Can an End-User Check the Status of a Ticket?

On our public portal, an end-user can submit a ticket and see the ticket ID number.  My question is two-fold:

How do we add users to the public portal?  I can add agents to the Desk, but that doesn't allow logins to the public portal.

How can end-users check the status of tickets?  Is there a way for non-agents to look up a ticket number and see a ticket status?