Select audio track to streaming

Hi,
I use tvheadend to record tv programs and it records all original audio stream in mkv files. I use an Samsung tv to watch the recorded files by streaming serviio. Serviio streaming first audio track but I need sometimes other audio track because my preferred language on some tv programs (channels) is not first audio track.
I found this topic where user can select preferred audio language but I did not find on my serviio 1.2. viewtopic.php?f=11&t=6688
Where can I find this setup on serviio 1.2 or how can I setup preferred audio language?
Thanks
sipi
I use tvheadend to record tv programs and it records all original audio stream in mkv files. I use an Samsung tv to watch the recorded files by streaming serviio. Serviio streaming first audio track but I need sometimes other audio track because my preferred language on some tv programs (channels) is not first audio track.
I found this topic where user can select preferred audio language but I did not find on my serviio 1.2. viewtopic.php?f=11&t=6688
Where can I find this setup on serviio 1.2 or how can I setup preferred audio language?
Thanks
sipi