The shopping cart takes the payment confirmation directly from the blockchain and then releases a direct download of the book.
The following coins can be used for making the payment…
Binance Coin (BNB),
If you pay with Monero, the shopping cart could have difficulties with matching the payment (which is kind of a feature of Monero). If it takes to long for the payment confirmation to process, just let me know and I can email the book.
Email to firstname.lastname@example.org if you have questions or something doesn’t work properly.