It's probably because your kindle account is registered in a different region. To buy Kindle books for others, select the Buy for others button and then enter the details for your gift recipients.Unfortunately, the book is not available for purchase on Amazon US and UK. Instead, it shows as "the Kindle title is not currently available for purchase." If there is a problem with your Amazon account preventing you from purchasing books, you should contact Amazon. Go to Manage Your Content and Devices and click Preferences. When I go to my orders and click manage content the dropdown box has several options but not one that allows me to enter the recipient address. Sign into Amazon's Manage Your Content and Devices page and click the Content heading at the top. Share books from Library. The book will automatically download and appear in your Kindle library.