Hello Plum_8,
You can change the playback language on your Apple TV with these steps:
1. On a Siri Remote or Apple TV Remote, press the Play/Pause button while watching a video to bring up the playback controls. Or on a remote for a smart TV, streaming device, or game console, press the button that brings up the video timeline.
2. Use your Siri Remote or Apple TV Remote to swipe up and select the Audio button
. Or use your smart TV, streaming device, or game console remote to navigate to the Audio button
.
3. Choose the audio language that you want.
If you want to set a default language for all items to play in, you can do that by going to Settings > Video and Audio > Audio > Audio Language, then choose the language that you want.
Change subtitles or languages for videos in the Apple TV app or iTunes Store
Cheers!