If you need to enable DRM, the below information should be helpful.
To enable DRM in Google Chrome, search for “protected content” under chrome://settings and enable it. By default, it is enabled but an extension may have turned it off for your privacy.
The Firefox browser will provide a one-click button for you to enable DRM so you do not have to hunt through all of the settings. To check to see if DRM is enabled, go to Amazon Prime Video and try to play any content.