To convert your USB printer to AirPrint, follow the steps:
Connect your CHIP to WIFI.
You will see a list of Wi-Fi networks; connect to the correct network.
After that, install CUPS and AirPrint on your CHIP.
Configure CUPS and install your printer.
Install “AirPrint” and this will convert your USB Printer into a WIFI AirPrint one.
Read more: https://www.printeralign.com/convert-usb-printer-to-bluetooth-printer