Install a Plugin in GeckoFX

Question

Hay, im making a browser and want to attatch a Plugin to my Geckofx browser. I simply looked how widevine was installed in firefox and made it like that. I copyed the gmp-widevinecdm from the firefox-profilefolder to the profile folder of my browser.

I experimented with these flags and configs

            GeckoPreferences.Default("extensions.blocklist.enabled") = False
            GeckoPreferences.Default("media.gmp-manager.updateEnabled") = True
            GeckoPreferences.Default("media.gmp-widevinecdm.version") = "4.10.1582.2"
            GeckoPreferences.Default("media.gmp-widevinecdm.abi") = "x86_64-msvc-x64"
            GeckoPreferences.Default("media.gmp-widevinecdm.enabled") = True
            GeckoPreferences.Default("media.gmp-widevinecdm.visible") = True

I simply want to implement DRM-support and really dont know anymore what to do :/

:)