Hi,
Was this the procedure that you had tried?
https://support.hp.com/us-en/document/c06447928
HP Printers - 'Encryption Credentials Expired' Error Displays (macOS, iOS)
The HP Color LaserJet Enterprise MFP M480 is listed in About AirPrint - Apple Support as a model with support for the driverless AirPrint technology. An AirPrint-enabled model should not need additional drivers, provided that the printer and the computer are connected to the same network (Wi-Fi router).
In case of difficulties with AirPrint, and if the setup is OK, one could try the following procedure:
Power off the Wi-Fi router, the printer, the Mac, the iPhone, 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 Mac. Power on the iPhone. Finally, power on all other devices/computers.
https://kaas.hpcloud.hp.com/pdf-public/pdf_2952853_en-US-1.pdf#unique_189
Add a printer to your printer list so you can use it on Mac – Apple Support (UK)
Reset the printing system on your Mac to solve a problem – Apple Support (UK)