How do I download HP LaserJet 1020 Plus printer drivers for MacBook Air M3?

You may have tried to download and install the following package from Apple.

HP 5.1.1 Printer Software Update - Apple Support

Earlier reports indicate that the use of an HP LaserJet 1022 driver from that package is possible with an HP LaserJet 1020 printer as well. However, the text says Not compatible with macOS v12 and newer, so do not expect it to work with macOS Sequoia 15 without modifications. If the package will not install, various solutions have been suggested for an HP LaserJet P1005 and other models, but the success rate is somewhat unclear.

If a compatible HP driver for macOS 15 cannot be found, or if another software solution is not possible, you may have to look for a workaround.

As Tesserax mentioned, Linux drivers are available for the HP LaserJet 1020 Plus.

https://support.hp.com/us-en/drivers/hp-laserjet-1020-printer-series/model/3329726

https://developers.hp.com/hp-linux-imaging-and-printing/supported_devices/index

If nothing else helps, you could perhaps investigate whether a small Linux-based Raspberry Pi print server would allow a USB-connected HP LaserJet 1020 Plus to be shared with a modern Mac (or iPhone/iPad) in an AirPrint-like way. Look upon this as an experiment.

Tesserax reported about using a Raspberry Pi 3 Model B+ for an old HP LaserJet printer.

Can I connect my laser printer to my netw… - Apple Community

Details about a Raspberry Pi print server setup (for a USB connection to a Kyocera laser printer) can be found in the posts by Techguyuk in Can’t print with iPadOS17 - Apple Community.

Have you checked the HP Support site to see if they have updated drivers for this particular printer model?

I just did a quick check and they only appear to have drivers for either Windows or Linux computers.