RAX120

> [...] When I go to http://www.routerlogin.net, I receive a notice that
> I need to be connected to the Router's WIFI network. [...]

   Welcome to what may be the worst error message in the world.  For an
explanation, try:

      https://community.netgear.com/t5/x/x/m-p/1365830

   Briefly, the idea is that "[www.]routerlogin.net" (or ".com") should
point to your own router, but that's true only if you use your own
router for DNS name resolution.  (Or, if the Netgear router can
intercept your DNS queries.)  Regardless, you should be able to get to
the thing using its IP address, if you can determine (or guess) that.
Normally, that would be something like "192.168.1.1" (for a plain
router) or "192.168.0.1" (for a modem+router), but it could be
different. ("10.0.0.1" is a typical alternate, for example.)

   General advice: An accurate quotation of an actual error message is
often more useful than an interpretation of an actual error message.
Usually works better in a Web search, too.  Copy+paste is your friend.