As nagol3002 said, The itch.io version does give you a Steam key/ It's available from the download page which you can view at the top of the itch.io page once you've purchased. The only reason you'll need a refund is if you can't or won't use Steam. There's a few reasons why that could happen, including Steam having been a known health hazard for some users for almost 2 years now with Valve actively refusing to fix the problem. Fortunately, even though it's kind of trash, Epic is at least better than Steam in that regard.