Wireless network of XAVN2001 doesn't show up

I can see it on the router's attached device list, but I can't connect to its IP. It shouldn't even be necessary to try to connect that way, of course. The setup instructions suggest using WPS, and then simply go on to say: "If your wireless client does not have a WPS button, you need to access the user interface of your client device to manually enter the wireless settings to connect to the extender." As I mentioned above, I can't get into the XAVN2001 to retrieve the wireless settings because the Powerline Utility doesn't show the XAVN2001 (or my router or anything). And even if I were able to retrieve the settings, the XAVN2001 would still need to show up as an available network connection on the PC for me to input those settings. That's the problem. (Windows lets you add "hidden" wireless network connections, but that seems to be a rabbit hole. This is supposed to be "plug and play" -- it says as much on the box -- not "plug and flail"!)