Support for custom RTP header extension (h265)

[samyjain411]

Hello,
I'm completely new to webRTC and have a question regarding RTP header extension for h265.
Is it possible to add custom RTP header extensions to send metadata along with a video/audio frame? If so, could you please provide some guidance?
For context I would like to send additional metadata along with the media frame for a specific use case and process it on the receiving end.
If this feature isn't currently supported, I'd like to know if there is a way I can extend the library to include this functionality.

Thanks!