1. You do not need to have kindle unlimited or a Kindle device to access the free copy.
HOWEVER, you will need to download the free Kindle app. This will allow you to access the eBook on any device.
2. You should not have to add any credit card information to receive your eBook. Please see the picture below for more information on accessing the e-book.
3. look at the photo above and locate the portioned underlined in red. This shows that the book is available for $2.99 (for non KindleUnlimited subscribers). When it is a promotional period, with the digital book on giveaway, it will show $0.00 to buy. You can then click on the price and the option to buy it should show up on the right side of the page. See below.
Again, YOU DO NOT need to have a kindle in order to view the material. You just need the kindle app, which is free and can downloaded through an app store.
4. Once you have added the eBook to your cart during the promotional period and accessed it through the app, you will have the eBook in your library for as long as you decide to keep it.
Please email firstname.lastname@example.org if you have any questions, or difficulty getting your free digital copy.