In this challenge, you need to look for a file named key2.txt in the place used to serve the assets for the main website
Amazon Web Services Storage Service (S3) allows file owners to set permissions on files. Historically, the rules "Any users" wasn't well explained and lead a lot of people to think only people in their Amazon account could access a file. However, this was allowing any AWS account to access the file.
It's essential to look for files that may be publicly available on the servers used to load assets.