You can adjust caption language in:
Settings → Caption Settings
Primary language
Primary language used by Bridge is English.
To view it:
1. Go to Settings → Caption Settings.
2. Under Caption Language, look at Primary.
Secondary language
Secondary language is optional and can be set if you want an additional language option available in-call.
To set it:
1. Go to Settings → Caption Settings.
2. Tap Secondary.
3. Choose the language you want (or set it to None).