Once you’re content with the seem of the eBook, it is possible to publish it. This does not publish your eBook to Kindle Immediate Publishing, but results in the .kpf file and you can add that file to Kindle Immediate Publishing, as an alternative to your Phrase file. Also, KDP https://maplepublishers.com/blog/how-to-start-your-career-as-a-self-publishing-author-with-maple-publishing/