You cannot download a prod.keys file from the internet legally or safely. Keys are console-specific. You must dump them from Nintendo Switch.
Windows often hides known file extensions. You might think your file is named prod.keys , but it is actually prod.keys.txt . hactool prodkeys does not exist top
hactool --keyset=/home/username/Downloads/keys/prod.keys game.nca You cannot download a prod
He moved the file to the correct directory, renamed it, and deleted the extra extension that Windows had helpfully hidden from him. hactool prodkeys does not exist top