Notes From Hiding is in Kindle Unlimited for a limited time, both in serial form, and as a complete novel. Until mid-September, it will be unavailable in ebook outside of Amazon. But, Lord willing, it will be back elsewhere in ebook as soon as the current contract with Amazon expires.
You don't have to have a Kindle to read Kindle books, by the way. There's a free Kindle app at Amazon that lets you read on other devices, like your computer.
Meanwhile, the trade paperback remains available in all the usual places.