HP Officejet Pro 9020

Hi,

Also, the HP OfficeJet Pro 9020 All-In-One Printer is listed in About AirPrint - Apple Support as a printer supporting the driverless AirPrint technology. An AirPrint-enabled model is compatible with macOS, and can be used without additional drivers, provided that the printer and the Mac computer are connected to the same network (Wi-Fi router). AirPrint works with wireless (Wi-Fi) or wired (Ethernet) network connections.

If you are using AirPrint, and there is a problem, you could try the following full procedure (in this order):

Power off the Wi-Fi router, the printer, the iMac, and all other devices/computers. Wait two to three minutes. Power on the router. Wait two to three minutes. Power on the printer. Wait a minute or two. Power on the iMac. Finally, power on all other devices/computers.

Have a look at > Reset the printing system on your Mac to solve a problem - Apple Support

+1 to Jan's suggestion. We just replaced a networked printer yesterday and it do not show up in the Printer sys Prefs until we power-cycled the router.

Glad to hear that, you’re welcome.