In the following link it says:
When a 1.3 client connects to a 1.3 server they agree on a resumption key (or PSK, pre-shared key), and the server gives the client a Session Ticket that will help it remember it. The Ticket can be an encrypted copy of the PSK—to avoid state—or a reference number."
I have read through the draft of TLS 1.3 and have only found that a Client sends an PSK-identifier, which is a number, that belongs uniquely to a PSK. I couldn't find any mention of "an encrypted copy of the PSK".
Am I wrong? Did I miss something in the draft? Because if I did not miss anything, servers would need to keep state of every PSK they have established, no?