Amazon seller can't open the delivery.

If your current reader doesn't open, there may be something wrong with it. Try another one. If it still won't open, there may be something wrong with the network settings. Reset dns, then open the reader again, and you should be able to log in. If you still can't log in, there may be something wrong with the website. If it is Amazon's own problem, you can contact the platform to log in later. Usually, the problems of the website will recover quickly.