Plex is one of the most popular ways to stream your own media collection, but there was no officially available app to play all Plex content on Linux – until now.
Plex revealed in a blog post today that the Plex desktop app (the client for playing content, not the server) is finally officially available for Linux systems. It is distributed as a Snap package, which means you need a distribution that supports Snap and the framework installed. Snap is installed by default on Ubuntu Linux and also works on Arch, Fedora, Pop!_OS, KDE Neon, openSUSE, Debian and other distributions.

Although it’s the same Plex desktop app available on Mac and Windows, it’s more or less the plex.tv interface with the added benefit of offline support (so you can save movies and other content to watch offline later). The current version of the app first launched on Windows and macOS in 2019, replacing the older Universal Windows Platform (UWP) version designed for Windows 10 and Windows Phone. Plexamp, an alternative app designed just for streaming music from a Plex server, is already available for Linux.
You can download Plex for Linux from the Snap store or by running sudo snap install plex-desktop
in Terminal on a Linux PC with Snap already installed. Plex says a Flatpak version will also be available at some point.
Source: Plex Blog