New to Plex - how to download subtitles automatically with Apple TV?

Hey there,
I’m using Plex on Apple TV 3rg Generation and Windows 8.1
everything works like a charm.
How can I download subtitles with my Apple TV or how to make the server download subtitles automatically ? it doesn’t seem to do that. i’m added OpenSubtitles as an agent and made sure it’s marked.
Thanks

When you marked OpenSubtitles as an agent did you click the settings link on the right? You can choose 3 languages and input your OpenSubtitles Username and Password.