Alexa Doesn't Read My Kindle Books

The Kindle book isn’t compatible or the Echo device is unresponsive.

Confirm that your Kindle book is supported by Kindle Assistive Reader on Alexa.
Unplug the power adapter from your Echo device and then plug it back in.
Ask Alexa to "Show my Kindle books," or use the Alexa app to see a full list of supported books.