Of course. You don’t need to use USB. Just plug in the NAS into an Ethernet port of your router.
It is very recommended, to use a wired network connection for the Plex server machine.
If you run out of Ethernet ports on your router, you can add an Ethernet switch relatively cheap.
See also Verbatim Powerbay NAS with Plex media server - #2 by OttoKerner
