Interesting - do you have any sources to read further?

Search for widevine decrypt. You’ll find code and forums where at least some L3 (software) keys are publicly shared. For high resolution on some platforms, you need L1 keys, but as far as I understand the decryption process basically stays the same once you have a working key.

Random article: https://www.ismailzai.com/blog/picking-the-widevine-locks

Claimed to be L1 key leaks (probably all blacklisted by now): https://github.com/Mavrick102/WIDEVINE-CDM-L1-Giveaway

You won't find a ton of up-to-date info that would let you do the same - the scene groups hold their methods closely specifically because of this cat-and-mouse game.