Each virtual card you create has its own unique details, so you can buy online without using your physical card's details. You can create virtual cards in both iOS and Web App. The money you spend comes from your balance, just like with your physical card.
They’re great for managing online subscriptions. If your real card gets lost or stolen, avoid updating your payment details everywhere.
You can manage your virtual cards by tapping “Cards” at the bottom of the Home screen.