Using only Lan connection when connected to SIM

Hello all,
I am trying to get it to where when my connection rolls over to my cellular, I want it to automatically disable the wifi connection, and only allow the lan connection to work. Does anyone have any insight how to do this?
Here’s some addtl info, just worded a little differently.
…… we are living in our RV full time but not yet traveling. Our park has good wifi but like all internet we have the occasional outage so we have att data package for our Pepwave router. Is it possible for when the router switches to the cellular data it can be dedicated for only LAN port only for a work computer, and the other devices wouldn’t work on the SIM card? If this is possible

I assume you mean on wan failure , it only allows wired LAN to connect.
There is a “on no internet option” that you can enable to have it tied to disable wifi.
This would only work on total loss of internet both wired wan and cellular.
One thing you can do is set a outbound rule with the source ssid of the wifi and enforce to WAN.
This means that anything wireless can only use the wired wan.
It would not automatically disable the wifi tho.