I don't know about leather cases, but there are many different kind of third party cases. Try to search for leather cases, for example, on Amazon and Etsy. Just make sure the cases are for your Kindle. Amazon especially is really good at recommending cases for other Kindle models than the one you searched for. You might search for "paperwhite 11th gen leather case" and Amazon might recommend you cases for 10th gen or earlier Paperwhite or for Kindle Basic.
Amazon's own cases for the current Kindles are pretty bad. Hard and sharp edges all around which hurt your fingers. I bought a Chinese cover that has silicone back, and it's way better than the Amazon's hard plastic case I have.