Awhile back I paid Amazon for the rights to watch a movie. It's the only movie I've ever bought the rights to view. And now ... I can't view it. I get an error message that I can't watch it because I don't have DRM enabled.
I'm running Waterfox 56.2.14 as my browser. It's a fork of Firefox -- it looks like, acts like, and runs pretty much all add-ons for the older Firefox.
Where can I find DRM and how do I add it to Waterfox?