I am very new to Kali and just going through the online training. In it, it refers to pinfo, which I believe you should be able to install using sudo apt update and sudo apt-get install -y pinfo. I am getting an error however telling me that it has no installation candidate. I am given to understand that this means that it is not recognised within the default repositories but a] Why would it not be, if it is part of the official Kali learning documentation and b] How do you find out if a package does exist in a repository elsewhere?