@James *******
It's ALL done by mail now. AND you send your original passport in when you post the packet so they can cancel it and mail it and the new one back to you.
I had an elderly friend renew their US passport recently and she got the old/new passport delivered to her door 12 days from the date we mailed the EMS packet to the US embassy in Bangkok
I messaged you the link on where you get the info to renew your US passport