Passing this off as your own work is still plagiarism, even if it's fanfiction. It'd be no different from someone finding your college/high school essay paper and passing it off as their own despite having done none of the work.

This is a blatant copy-and-paste from another author's works. Being the author writing this review, I gave no authorization for the work to be posted here, nor was I ever contacted about doing so.

How have you contacted the author? He’s written nearly 60 chapters of this story and doesn’t appear to have made any shoutouts or public okays for people to post his work.