This is general feedback in case it is useful to the developers. I don’t particularly mind downloading .deb files and updating manually.
"W:GPG error: https://downloads.plex.tv/repo/deb public InRelease: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 97203C7B3ADCA79D, E:The repository ‘https://downloads.plex.tv/repo/deb public InRelease’ is not signed., W:Updating from such a repository can’t be done securely, and is therefore disabled by default., "
Ubuntu 18.04 64bit
