For most people, creating an account and entering their information into the register dialog is enough. If they have trouble, the document is meant to be helpful in diagnosing issues.
Can you fix this ridiculous mess with registration!? First of all IT DOES NOT WORK and I don't want to spend time doing all the tricks that you require. How about you do all of the magic under the hood when you process a buy order?
and yes, I cannot post a screenshot here in the forum, so all I can say is that the web site says that "Error" "Failed!". (in 1995 I'd attach an image, in 2019 Ctrl+V has to be able to paste screenshot, just like in gmail or any other modern web app).