Open the Wallet app on your iPhone
Tap the plus sign in the top-right corner
Tap Debit or Credit Card
Tap Continue
Choose Add a Different Card or select a card from a previous device if available
Position your card in the camera frame or enter the card details manually
Follow the on-screen verification steps from your bank or card issuer
Complete the verification process
Tap Done when the card is added
If needed, add the card on Apple Watch through the Watch app under Wallet & Apple Pay