How to add a card as a payment option in Paypal:

Create or sign in to your Paypal account.
Go to Wallet.
Click Link a debit or credit card.
Enter your card information and click Link Card.
Follow the instructions in the pop-up window to complete the 3DS verification.

In some cases, in order to ensure you’re the card owner, Paypal may ask you to confirm your card. If you see a “confirm credit card” link in the card details section of your PayPal Wallet, you’ll need to confirm your card before you can use it with PayPal. If you don’t see this link, you can begin using your card right away.