Why would I want tor read that when I already know how it works?

As Amazon will inform you if you're not an American, they will withhold up to 30%

Might I suggest you read up on American tax treaties. It depends on the agreement that America has with each country, and it's different for every country. In Malaysia, Medium withholds 30%. For Portugal, it withholds 10%. For South Africa and the UK, Medium doesn't withhold anything.

This is a non-refundable tax.