DRM issue on 6700K with rx580 on Big Sur 11.2

Hi,

After updating to Big Sur I tried playing series on AppleTV+ but it just close and black screen. What I found in what evergreen manual where it mentions

*AMD GPU video decoder preference can be chosen through preferences overrides for some types of DRM content (like Apple TV and iTunes movie streaming)

UNDER LIST OF OVERRIDES it mentions

List of overrides:

• defaults write com.apple.AppleGVA gvaForceAMDKE -boolean yes
  forces AMD DRM decoder for streaming services (like Apple TV and iTunes movie streaming)

I am just not able to find out where I need to put these lines to make my AMD card just play the content on AppleTV+ using imac17,1