If you want to use a PostScript printer under any Snap-supporting operating system this is the software to use. It already support several thousands of different printer models and if your PostScript printer is not explicitly supported, you can add its PPD file (PostScript Printer Description file, comes with the printer's Windows/Mac/Linux drivers) or resort to generic PostScript support.
If your PostScript printer is from HP you can alternatively use the HPLIP Printer Application (https://snapcraft.io/hplip-printer-app). Use the HPLIP Printer Application if you want to print and scan simultaneously on a multi-function device and PostScript Printer Application if you want to be able to query your printer for its installed accessories (like extra trays, finisher, duplex, ...).
This Printer Application emulates a driverless IPP network printer (IPP Everywhere) for each physical printer set up with it, so your computer's printing environment discovers it automatically and makes your printer(s) available for printing. Like on a physical network printer there is a web interface for administration, here especially also for adding and configuring printers. You find it with your browser under https://localhost:8000/. Note that currently printers have to get added via the web interface to use them. In the future, there will be utilities to easily find non-driverless printers and find the correct Printer Application for them.
With modern printers usually being driverless IPP printers, classic printer drivers, installed under CUPS by its web interface or a printer setup tool, are deprecated and replaced by Printer Applications which emulate driverless IPP printers as this one.