Let's not do that or get into why the costs would be about 50 bucks for each device per month. So let's move on.

The LAN is on the LAN ports of the router which is where we connect this switch. You should run a cable from the router to the switch and you are done.

Another thing to try and I don't suggest it due to how WiFi is a finite resource is this thing.
https://www.amazon.com/NETGEAR-Universal-Ethernet-Adapter-WNCE3001/dp/B005N6XBDO which is then configured and then the LAN port on it goes to your switch.

OR a powerline bridge from your router back downstairs. Example:
https://www.amazon.com/IOGEAR-Powerline-Ethernet-Bridge-GPLB200K/dp/B013FD5RSS