Encrypted-media header in embedded iframe

I’m developing a confluence macro that returns an iframe with a video player. The video is encrypted, so we require the header allow= "encrypted-media;" header in our iframe.

The Problem
Because dynamic confluence macros are deployed inside a Sandboxed iframe, the call to the Encrypted Media Extensions API (EME) is denied, and the video doesn’t play.

Is there any way to add this header to the parent iframe? Or any other way to get around this access issue (in config, for example)

Thanks in advance!