I'm assuming the USB port can be used to connect a range extender...
The USB ports on most Netgear routers are for printers or for storage devices. That is what it says in the manual for your device.
I have never seen any suggestion that you can use USB for a (wifi?) range extender. That is usually in the hands of a LAN port, or the router's own wifi.
What are you trying to do?
Just another user.My network DM200 -> R7800 -> GS316 -> PL1000 -> Orbi RBR40 -> Orbi RBS50Y -> RBS40V