Where are Settings?

It sounds like you're following instructions for an iPhone or iPad, not a Mac. On your Mac the app called Settings on an iOS device is called SystemPreferences.

Use Wallet & Apple Pay on Mac – Apple Support (UK)

Note this:

On your Mac, choose Apple menu  > System Preferences, then click Wallet & Apple Pay .

It's a great time for a new computer.

But if that is not a realistic possibility, or you need to wait for one to be built for you, your Apple Card does come with a conventional credit card number, expiration date, and CCV code. You can enter those manually as if it were a non-magical card.

WHICH settings? for what?

Apparently it requires Touch ID. If your Mac doesn't have that then there's nothing you can do.