Add Audio Track Switching & Subtitle Support to Web Media Player (Telegram Streaming)

I need an experienced developer to add audio track switching and subtitle support to a web-based media player.
My project streams media files stored on Telegram to a web streaming page.
The entire codebase is already available on
Requirements:
Add audio track switching in the media player (if the video has multiple audio tracks)
Add subtitle support and display subtitles if available in the media file
Features should work during live streaming/playback
Media source is Telegram-hosted files
Integration should be done in my existing code
Expected Outcome:
Users can select different audio tracks from the player
Users can enable/disable subtitles when available
Smooth and stable playback without breaking existing functionality