You don't need to download anything.
Just activate subtitles in settings and if you want it automatic choose Swedish as default langauge in language settings for videoplayer.
But this only works for DVB subtitles.
For Teletext subtitles you need to use something like TVheadend that converts Teletext subtitles to a format that Kodi understands.
Activate subtitles in subtitles settings or with 'L' key.
You can get it automatic if you go to language settings under Player settings and change to Swedish.
If someone wants to try TVHeadend it's easy to do with an LibreELEC install on boxes that supports it but i still recommend something more powerful than a small box.
TVheadend works fine but needs little work for everything to work and some important settings that needs to be done like setting maximum input streams to 1 and turn off all types of automatic scanning.