Wifi security code for Model No. R6400-100NAS

[Omegaman66]

Netgear AC1750 SMART WIFI ROUTER
802.11ac Dual Band Gigabits

[plemans]

There's a support site with access to manuals, firmware, install guides, etc.
Go to https://www.netgear.com/support/
Type in your model number and from there it'll take you to the above.
Its a great resource to start with.

[michaelkenward]

Look at the label on the R6400. This has the default wifi SSID and "Passphrase".

Maybe that is what you mean by "Wifi security code". That is not a label that appears in any Netgear manual.