Android 10 will bring native support for captions, which can show up in real-time over videos that might not have support for captions. For example, if you are scrolling through Instagram and suddenly a video starts auto-playing, Android will show you captions on the screen.
What’s more, Live Caption will work even if you’ve put your device in Airplane Mode, or if you don’t have internet access.
Go to “Settings”-> “Accessibility”-> “Captions”, touch toggle to active captions function