Command not working, why?

In the introduction to cybersecurity course, I am in the “decrypt secret messages” and I don’t understand why =

$ cat letter_3.txt | tr "K-ZA-Jk-za-j" "A-Za-z"

is not giving me the password of “LaserBeamsDestroyKittens”

nvm I figured it out

Care to share, in case others have a similar problem? :slight_smile: