Can I publish PLR ebooks to Amazon Kindle?
As per Amazon Kindle's Content Guidelines which can be viewed here https://kdp.amazon.com/en_US/help/topic/G200672390, PLR cannot be published in its marketplace.
Refer to the section 'Public domain and other non-exclusive content'.
PLR cannot be copyrighted due to the nature of the content being distributed amongst many others, therefore the content is categorized as non-exclusive.
Our recommendation if you do want to publish on Kindle is to rewrite the content and redesign the book cover.