Streaming from Android to Roku – Subtitles?

Greetings,

I have Localcast working just fine streaming from my Samsung Galaxy 7 running Kodi to my Roku. Now my issue is that I cannot seem to figure out how to get subtitles to stream from this to the Roku. I was at my friends place and remember seeing an option in LocalCast that was like “download subtitles through opensubtitles.org” and when you click it you input your opensubtitles login info etc. That was on a Chromecast. While streaming to roku, it seems that option is replaced with a “route audio to device” option instead. How do i download subtitles?

If it is impossible to add subs when streaming to a Roku from a phone (sounds like it should be unlikely), Is there seriously no way to stream from Kodi running on my PC to my roku? blah

Thank you