Looks like the iOS documentation is not updated.
I did everything mentioned in the document but still some how it wasn't showing the card number nor the expiry date later I figured out that content path mentioned in documentation was the reason it was't working I had to change the path and it worked.
cardNumberLabel.contentPath = "cardData.cardNumber" // didn't work not showing any data
expDateLabel.contentPath = "cardData.expDate" // didn't work not showing any data
Instead I had to change path to this.
cardNumberLabel.contentPath = "id" // working
expDateLabel.contentPath = ""expiry_mm_yyyy"" // working