You can save several cards in your LiveXP "Wallet" and switch between them.
If you want to change the card you have, delete it and save another instead.
1. Click on your photo in the upper-right corner of the screen
2. Choose "Wallet" > "Payment settings"
3. Delete the card from the "Payment method"
4. When you make a purchase next time, enter new credit card details and check the "Save this card for easy payments" box.