Not possible. Suggest you investigate other options.
At some point Plex needs an Internet connection. It can work for awhile without one, but at some point Internet connectivity is needed.
Specific to the Plex SmartTV apps (LG, Samsung, etc), the full app is not stored on the TV. The TV holds a “loader” application. When the TV is powered on, the loader app downloads the full app from the Internet.
You can get around some limitations by bypassing authorization or running the server as unclaimed, but that only goes so far.
See this How To article. It has additional information.
