if it remains in that terribly insecure state by default until you give it a connection to a network, unfortunately the only thing to do might be to give it the password to a $20 mikrotik wifi router (in a 20MHz 2.4GHz channel) as an AP, so as to not pollute the empty radio channel spectrum in your house, that has no connection to the outside world. What an ugly hack.

Or give it the password to a secondary ssid set up on your main wifi, that goes to a dead end VLAN with no route to anywhere.