Fourteen days from purchase, full refund, no reason needed.
Reply to your order receipt, or email with the order number. Refunds go back to the original payment method through Lemon Squeezy, our checkout provider, and usually post within five business days. The license for the product ends when the refund is issued.
Paperbacks sold on Amazon follow Amazon's return policy, not this one.
If you are in a jurisdiction with a statutory withdrawal right for digital content, that right applies as the law provides and nothing here shortens it.