cannot access router login to do update

> [...] This makes no sense to me [...]

   It makes no sense, period.  It seems designed to confuse.  What's
true (and what the message never mentions) is that you're not using your
Netgear router as your DNS server.

   The DNS server in a Netgear router is programmed to intercept a name
like [www.]routerlogin.com, and return the LAN IP address of the router
itself.  (Other stuff normally gets passed through to your ISP.)  This
works as desired, IF you use the router as your DNS server.

   If you use any real-world DNS server, then you get directed to
something like an Amazon Web Services rent-a-computer (currently:
52.27.105.210, 54.201.206.72) whose Web server sends you that
misleading, unhelpful error page.  Wired or wireless makes no
difference.

> Access the router via the IP address(192.168.1.1).

   That should work, unless someone has assigned a different address to
the thing.

   If you want the [www.]routerlogin.com thing to work, then you need to
use the router as your DNS server.  How you'd arrange that would depend
on the (unspecified) device (and OS) where you're running that
(unspecified) Web browser.

I am not able to log in to 192.168.1.1 either.  I receive a box:  Authentication Required  http://192.168.1.1 requires a username and password.  Your connection to this site is not secure.  What is next step?