The card saved on file is encrypted.
You won't be able to see the full number, even us (as platform) cannot see the full number. It is by law and for security purpose, that when client authorized the card transaction, the card number can only be saved with encryption.
The Stripe credit card processor integration enables you that once you have "card save on file", the next time when you check out the appointment and "charge card on file", the system will charge without needing to know the exact card number.
The card saved on file can be found under client profile > payments. 

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