Install vlc-plugin-vlsub by entering the following commands in the terminal:
sudo apt update sudo apt install vlc-plugin-vlsub
Description:
VLC extension to download subtitles from opensubtitles.org
Search and download subtitles from opensubtitles.org using the hash of the video currently playing or its title.
Homepage: http://addons.videolan.org/content/show.php?action=content&content=148752
Version: 0.10.2-2
Section: universe/video