There are a hundred and one different ways to make a Kindle ebook. many start with Microsoft Word, and now there's an option that both begins and ends there.
Amazon has released a Kindle Create add-in for MSWord that can be used to make a Kindle ebook. I don't have Word (Libre Office for the win) so I cannot test it. But according to the download page:
- Format your manuscript by specifying styles like Chapter Title, Chapter Subtitle and others.
- Save time by using pre-formatted sample pages like book title, copyright, dedication to complete your book.
- Preview your book any time on as it would look to customers reading on Tablets, Phones and Kindle E-readers before publishing.
- Work in Microsoft Word and publish your .doc/.docx manuscript with Kindle Direct Publishing.
The install file requires a PC with Word 2007 or newer, just not a PC that runs macOS.
If you install the add-on, please do let us know how well it works.
P.S. There's no Kindle-making extension for Libre Office, but Writer2Epub fills a similar role.