Okay, copywrite is not actually a word. Copywriting is, and an equally important element in self-publishing your book as successfully as possible on the market.
Copywriting, as spelling would imply, has less to do with copying anything and more to do with writing. So what is copy? Copy in this case as a noun is, according to Merriam-Webster, “something considered printable or newsworthy.”
Copywriting by that definition is akin to marketing, and helps promote your book once published. It is perhaps most effectively implemented on your book’s back cover.
Studies show that a book has around 8 seconds to convince the reader to buy it. 3 seconds for the cover image to captivate them and 5 seconds for the back cover copy to sell them on the contents. The fact is most authors don’t know how to write sales copy. Sales copy is an entirely different animal, after all. A skill honed by advertisers and marketing folks.
A handful of quality self-publishers offer those services. Look for that option when choosing yours.
Have fun and keep writing (just not copy).