Yea, it's not there and I've been trying to figure out why too.
The instructions Lei provided are not coherent to WSUS's interface.
If you right click on Updates and search for either the KB number or "enablement" - you don't see that package.
Others have said it's within the "Windows 11, version 23H2 x64 2023-10B" (and now the subsequent -11B) update, but I don't have any confirmation of that.
I can confirm that many of my systems have upgraded using the -10B update.