Where can I download AirPrint to my iMac?

From 'Related Article': About AirPrint

Print documents from your Mac - Apple Support

//support.apple.com/guide/mac-help/print-documents-mh35838/mac

If your printer is Not on the List of the supported

models, you may have to look & get drivers from

the Maker's site; sometimes out of region drivers

may be available when model numbers mismatch.

The manufacturer's support may have more drivers.

Your model might be listed in Related Article.

ludmila225 wrote:

Where can I download AirPrint to my iMac?

AirPrint has been built into macOS for a while; starting with OS X 10.7 Lion.

..ludmila225..

An option within AirPrint exists, to use USB (cable) instead of 'wireless'

that's something should there still be an issue; otherwise try all options.