I have all the updates. How to scan on my MacBook Air?

The following may help: Scan images or documents using your Mac - Apple Support

Note that if your MacBook Air is new, it would have macOS 10.15.x rather than 10.14 shown in your signature.

If the above doesn't help you may want to reply with more information about the OS version and about the scanning device.

The following download from HP may help. https://support.hp.com/us-en/drivers/selfservice/hp-envy-4500-e-all-in-one-printer-series/5304875/model/5304876

And read the following: https://support.hp.com/us-en/document/c06188214

So far, I'm the only person on this thread that is trying to help you.

If my previous two replies were of no help to you, you may want to reply with some details.