Go into settings, by clicking in your profile picture in the top right corner. You’ll get to a screen where you can block the card with just one click:

When your card is blocked, this is how the screen will look, you can also unblock your card by clicking the button again:

To be able to have this function, your card must have been activated from the main screen. If you need to block it but haven’t activated it yet, contact us through the chat in the app or through email to soporte@fondeadora.com