Then it also has some issues with Chrome, Vivaldi, Opera, and Firefox – all on Windows 10. All of which I've tested in the last day.
If there's any commonality in those things, it's that all of them are running some form of ad blocker as well as block pop-ups. But none of them are giving me a notification that a pop-up is blocked when posting the key to Steemit, so that's unlikely to be the problem.
Or, essentially, I don't think I've talked to anyone for whom it has worked yet. Testing it on multiple browsers here hasn't actually worked. Not only hasn't it worked, there's no indication that it's supposed to be doing something – the button just bounces and nothing happens.