They certainly don't want to make it easy, do they? The cynic in me is pretty certain that it's on an awkward, out of the way separate website for a reason. This is the link you'll need, but the page is currently down and giving a 502 gateway error. Try it again tomorrow, and hopefully the page will be up and running again. I'm currently waiting on my S21 Ultra order (so excited!) and have visited the page a few times in preparation. It's definitely correct, but is temporarily down I think.
