Apple Pay itself only requires the information from the card (including the CVV code). But many banks require an additional verification step, e.g. by texting a security code to a known phone number. In some cases it may also depend on which device you are activating the card on (e.g. if you do it on a phone with a phone number that the bank knows, they may skip additional verification). You should receive a prompt that explains what you need to do.