Port Forwarding Not Visible

> Model: C3700|N600 Cable Gateway Docsis 3.0

   Is that accurate?  C3700 or C3700v2?  Look for "Model" on the product
label.

> [...] I tried accessing the router [...]

   "accessing the router" how, exactly?  Some app or other?  Web
browser?  Other?

> [...] to set up a port forward but the option to do so doesn't pop up
> on my menu in the genie.

   Huh?  "pop up"?  It won't look for you; you might need to look for
it.

   _Which_ "the genie"?  Ever helpful, Netgear uses the name "Genie" for
more than one thing.  Netgear routers have a web-browser interface
called "Genie", and Netgear offers application programs for various
computers/tablets/phones, which are also called "Genie".  Which "the
genie"?

   Visit http://netgear.com/support , put in your model number, and look
for Documentation.  Get the User Manual.  Look for "port forwarding"?

> [...] Any reason this might be happening?

   Any reason _what_ might be happening?