Plex is incredible at automatically fetching subtitles. If you name your file correctly (e.g., Zombies 2 (2020) edition-Disney+.mkv ), Plex will download the correct from its open-subtitle agents in the background. You can also manually upload an .srt file via the web interface.
Here are several concise, useful text snippets you can use for "Zombies 2 subtitles" (copy/paste-ready for captions, file headers, or website use): zombies 2 subtitles