If you don’t have this ability because the TV isn’t close to a router or if the manufacturers get so scummy that they no longer include Ethernet ports, you could accomplish this by setting up a “burner” hotspot on your phone and doing tethering. Change the name and password to something you’d never use and then let the TV connect to that and then change it to something else. TV may remember it but it won’t find that exact combo again unless you want it to :)