You run a server on a machine inside your house, it can be any computer on your local LAN/wifi, but it’s obviously best if it’s a machine that’s always on. I use a Raspberry Pi 3B+ (these can be had for about $50) that I have plugged into my wifi router and it’s running a little program called Kiwix-Server (free and open source). You download the WP file (it’s a huge single file with a .zim extension) and point the server to it and boom.