Automatic reading of subtitles on TV and Netflix

Hi, recently I heard somewhere that it is possible to turn on automatic reading of subtitles by VoiceOver in movies, but unfortunately I am not able to set it up. It reads everything except subtitles. I tried in the AppleTV aplication and in Chrome and Safari on Netflix because I mainly care about these two portals. Can someone tell me exactly how I should set it to read only subtitles in movies?

I'm working on a MacBook Air 2020.

Thank you in advance for your help.

Regards.