Question about Netgear ax router

I have a quick question. If I were to buy the netgear nighthawk ax router, does anyone know if I can hook up the netgear nighthawk x6s wifi mesh extender or netgear nighthawk x6 ac2200 tried band mesh extender directly via ethernet? I have my router upstairs at one end & my extender downstairs at the other end & its connected by ethernet. I’m not looking to go to a mesh system.

I am not specifically familar with the NetGear Nighthawk, but I have read that some of the Nighthawk models run DD-WRT firmware, which I am familiar with… So let me expand on that with my area of familiarity.

My configuration.
2 @ TrendNet AC1750 WiFi routers with DD-WRT.

They are installed about mid point in the house, fully accross from each other.

Router #1. Running as a regular router, serving DHCP, local DNS, VPN, and DLNA media server. WAN cable comes in from cable modem to WAN port, I have 4 ethernet ports on this router. Ehternet port #1 is cabled via Category 6 ethernet cable to… Ethernet ports 2-3 uplink to the ethernet switch for my home office, and VoIP adapter. Port 4 is orphaned but used to have the uplink to the Iris hub cabled to it…
Router #2. Running in Wireless AP mode. All it is doing is acting as a repeater, giving me a full WiFi bubble that includes the entire home and property. The cable from Router #1 is piped into the WAN port. The ethernet ports are cabled to my smart TV and game consoles in the master BR…

Not sure this helps, but it maybe?