The website jupitersclaim.com appears to be an in-universe site of Ricky "Jupe" Park (Steven Yeun), who runs a theme park that's presumably located in the same area as OJ and Emerald Haywood's (Daniel Kaluuya and Keke Palmer) beleaguered ranch. The visitor is greeted with a cheerful message from Jupe, who introduces himself as a former child star. You can explore various attractions of the theme park, and read their descriptions. It all seems like a perfectly regular promotional site for a minor sourist attraction ... with one little catch.
Every once in a while, the site takes a night-time appearance, and things get all kinds of strange. The mascot's expression turns into a glazed look of shock and worry, the skies go dark, and the descriptive texts take a new, ominous tone. "While you're in here, who knows what horrors might be happening out there," the page for the Theatre attraction proclaims. The page for the bank starts preaching against the evils of currency, the General Store deals ominous warnings about the park, and the description for an innocuous-looking wishing well called "Winkin' Well" suddenly gets very, very strange indeed. "Look down into the well," it reads. "Look up toward the skies above. Whatever you may wish, it will not change anything. It cannot be undone. It cannot be unseen. If you fear the darkness that lies ahead, peer into the well and pray you may be spared."
Jordan Peele revealed the website on his official Twitter account, and by the looks of it, Jupe's creepy Western village attraction will provide an appropriately "nope" location for the movie — waxwork cowboys and everything.