Installing plex on Ubuntu is much easier with the official Plex repository.

What is Plex

Plex is a streaming media server that lets you organize your video, music, and photo collections and stream them to all of your devices at anytime and from anywhere.

What version of Ubuntu is required

At time of writing, this process is available from Ubuntu 16.04 Xenial Xerus. I have tested successfully with Ubuntu 16.04 Xenial Xerus and Ubuntu 18.04 Bionic Beaver.

Prerequisites

Sudo privileges.

Install Plex Media Server

  • Add the Plex repository

    The following commands will add Plex’s GPG key to the apt sources keyring and create a new file containing an entry to the Plex repository:

curl https://downloads.plex.tv/plex-keys/PlexSign.key | sudo apt-key add -
echo deb https://downloads.plex.tv/repo/deb public main | sudo tee /etc/apt/sources.list.d/plexmediaserver.list

  • Install Plex

    With the Plex repository enabled, update the apt package list and install the latest version of the Plex Media Server with:

sudo apt update
sudo apt install plexmediaserver

  • Updating Plex

    Updating Plex from now in is as simple as updating your packages

sudo apt update
sudo apt upgrade

… or my favourite

sudo apt dist-upgrade

Cheers
Wayne

Linuxize: How To Install Plex Media Server on Ubuntu 18.04
My Plex Media Server on PAGANI