To print to a classic printer, you'll need to use an application on your desktop which will share the printer over your wifi network.
Connect the computer and the iPad running LumaBooth to the same network either using a wireless or wired connection. Printing using LumaBooth Assistant does not require an internet connection.
a) Wireless Connection
Connect both your computer and iPad running LumaBooth Assistant to the same WiFi network. If your access point has two networks for 2.4Ghz and 5Ghz, make sure both devices connect to the same network. You should never rely on a venue's WiFi as the large majority of them block communication from different devices on the network such as your computer and iPad.
b) Wired Ethernet
For a more reliable connection in conventions you can use an Apple USB Ethernet Adapter to connect your iPad to your network. You'll also need the Apple Lightning to USB Camera Adapter. Connect the iPad to the Camera Adapter, connect the Ethernet Adapter to the Camera Adapter, connect your charging cable to the camera adapter, and finally connect an Ethernet cable to the Ethernet adapter.
c) Wired Lightning Cable - Mac Only
If you are running LumaBooth Assistant on a Mac, you can alternatively connect the Mac to the iPad running LumaBooth with a USB to lightning cable.