Display an error if a user tries to update a new card number to the same one.

Hello! I have been testing out the Pro Sites plugin and want to know how I can display an error to the user if he/she enters in the exact same card number that is already on file if they attempt to "Replace existing card" with a new one. I tested it out but it seems like it just returns the message "Your payment details have been updated successfully". Instead I would like to have that say something like "Sorry the card number you entered is already the current one on file, please try another one!" How can I do this? If you have any articles or code that I can integrate please let me know. Thank you :slight_smile: