Widevine Content Decryption Module completely missing
I am using a Raspberry Pi 400, which is 64-bit, but Mozilla Firefox automatically downloaded version 78.10.0esr (32-bit), and when I look in 'add-ons' and then 'plugins' in order to access the Widevine Content Decryption Module provided by Google Inc., it isn't there. It is not mentioned anywhere at all, and so I am unable to watch Channel 4, which requires I enable DRM content.
Please help? Thanks.