Do I REALLY have to log in each time I open new Macbook Air?

That should be all that’s required for Apple Pay on a Mac. Please review the support article I linked below if you need additional assistance.

>>Make purchases

1. When checking out from an online store, click Apple Pay.
2. If you have more than one card on file with Apple, you can choose which card to use. You can also enter a new shipping address and contact information.
3. Place your finger on Touch ID to complete the purchase.
4. If you haven’t set up Touch ID, you can tap the Pay button in the Touch Bar and enter your password. If your Mac doesn’t have a Touch Bar or you’re using a Mac with Apple silicon, you can double-tap Touch ID and enter your password.

Note: If the lid on your Mac is closed, you can complete your purchase using Touch ID on your Magic Keyboard (available on some models), or on your iPhone or Apple Watch and a card associated with that device.

If you haven’t set up Touch ID, see Use Touch ID.

If you have a Magic Keyboard with Touch ID, and you can’t use it to complete a purchase, see the Apple Support article If Touch ID isn’t working on your Mac.<<

Use Wallet & Apple Pay on Mac - Apple Support

Do you have biometric login enabled?

Your welcome.