It's a step-by-step process. My suggestion is to not think it through, and to follow the instructions.
I'm something of a techno-geek yet had trouble with the process until I stopped thinking and just followed step by step, no deviation, and got registered and now uploads are no problem at all. Could they have made it simpler? Absolutely! Will complaining fix it? Probably not. I gave in and just followed the process step-by-step and it does work. Don't overthink it and just do it.
Good DX to you!