It's kind of weird setup issue. I'm using 4G router and it's far away from my home (~400m), together with a wifi broadcaster to cover my house with wifi.
So now I want to setup my C7 hub and noted it need a LAN point. (I wanted to replace my SmartThings hub that's connected to internet via WiFi, which is slow some time, reason to change to Hubitat).
how do you setup LAN point out of wifi?
Does Hubitat able to connect to WiFi directly for setup purpose?
Your need to convert your WiFi to LAN
Ok so does this device not have a LAN connection? If not you can get WiFi devices that act like clients that convert WiFi to LAN. You would then connect this to a network switch which would give you X LAN points to use.
Why not use a PLC adapter?
Assuming all sockets use the same power circuit, this will be an easy way to bring LAN to wherever you want.
Have but it's very far, I mentioned it's 450m away.
Do you know any product that can do that?
Use a WiFi Extender to receive the WiFi signal and convert it to wired Ethernet for connecting to your HE.
Plenty of extenders like this, such as TP-LINK AC750 Wireless Range Extender
Or try one of these, as suggested above by @Mr.Olsen :
[TP-Link AV1000 Powerline Starter Kit - Gigabit Port, Plug&Play, Ethernet Over Power, Nano Size, Expand Home Network with Stable Connections, Ideal for Smart TV, Online Gaming(TL-PA7017 KIT) https://www.amazon.com/dp/B084CZMYNM]
Yep, bringing a WiFi signal fast and lossless over the distance of 400m, maybe through walls and other obstacles, will be quite a challange.
Assuming your rouer has at least one LAN port, the devices mentioned by @672southmain may be the most reliable and also affordable solution.