Apple AirPrint is a driverless connection protocol - that requires a compatible Printer to be wirelessly connected to your WiFi network. A high proportion of modern printers intended for Home, SoHo and Business environments now support AirPrint.
If your printer is not compatible with AirPrint, there are alternatives.
Some printer manufacturers have a suitable companion App that provides Print capabilities for mobile devices, often using a web-based print service. Others can print directly if the App supports other network printing protocols.
You might also consider connecting a non-AirPrint printer to a PC or Mac computer - and install a “helper application” that allows the computer to emulate AirPrint capabilities; one such option is Readdle Printer Pro, for which suitable software for PC is available. A link to the PC software is included from this page:
https://readdle.com/printerpro
A further alternative is to consider installing a dedicated Print Server Appliance on your network - and connect your printer to this. One example is the Lantronix xPrintServer.
The remaining solution is to simply replace your printer with one that is AirPrint capable.