How do I play MPD with Clearkey?

[MirazMac]

Hello. I'm confused to the usage of ClearKey DRM. As the documentation only mentions using local files and keys. However for remote MPD streams, how do I use it? For example, in JWPlayer for web, I use the following DRM configuration

drm: {
   clearkey: { keyId: "KEY_ID", key: "KEY" } 
},

But how do I fit this into the better_player DRM configuration.

I tried this but unfortunately it doesn't work.

      drmConfiguration: BetterPlayerDrmConfiguration(
        drmType: BetterPlayerDrmType.clearKey,
        clearKey: '{"KEY_ID": "KEY"}',
      ),

I also used BetterPlayerClearKeyUtils.generateKey({"KEY_ID": "KEY"}) but that too didn't work.

KEY and KEY_ID being the placeholders for the actual keys. Please advise if anyone can. Thanks a lot.