https://www.amazon.co.uk/gp/aws/cart/add-res.html? - mobile friendly but doesn't track orders and clicks since Mobile Apps are prohibited by License Agreement and Terms of Use https://affiliate-program.amazon.com/gp/advertising/api/detail/agreement.html
https://www.amazon.co.uk/gp/aws/cart/add.html?
https://docs.aws.amazon.com/AWSECommerceService/latest/DG/AddToCartForm.html