FreeNAS will then start the package installation which can take 5 to 10 minutes Once Plex is installed, go to Storage, and then Pools in FreeNAS If you do not already have a pool, create a separate pool for your media, I creatively called mine Media.Note also that you should do this regularly as the repository will change over time. Looks like you just haven't updated your package lists, this is missing from the link that you gave - sudo apt-get update This should download the list files from the repos in /etc/apt/sources.list so that apt-get install knows what packages to look for.By default, Kali Linux doesn't come with the necessary source links. Like other Linux distribution Kali Linux also needs a dedicated source to download and install the packages we need. If there is no sources list or bad sources list on the Linux system it will result in 'E: unable to locate package' error.For Ubuntu 18.04 with python 3.6.5 the python-pip package will install after : sudo add-apt-repository universe sudo apt-get update. Done Building dependency tree Reading state information. I am unable to locate package python-pip: Reading package lists.Done building dependency tree reading state information. Done E:Unable to locate package update'.