You don't need to have an adress in The USA. To give you an example: I live in France and there is amazon.fr.
Yet I sometimes buy on amazon.de and use my french adress...
It makes sense since you are within the European Union, however, I ask because when someone buys gift cards on websites like Bitrefill, a warning appears to whoever plans to buy cards for Amazon USA. Such warning is about the restrictions I mentioned.
That is something that has stopped me from buying them in the past.