If the delivery deadline has not passed, you can confirm and validate the transaction at the time of delivery, by entering the 10-character code in the dedicated field after pressing the « Code » button, i.e. from here:

Or from here:

This code is visible on the deliveryman’s transaction summary page, and he will need to give it to you to enter it and finalize the transaction. Make sure you have a good internet connection to finalize the transaction.

Once the correct code has been entered, a confirmation page will be displayed.