It's almost always going to be easier to obtain them through other means.
In the past, I've had good luck with StreamFab. It's expensive and Mac/Windows only, I believe. I had a smallisj use case and was able to automate mac address changes on a VM so could get by with the free trial. Been a while, so I can only vouch that it used to work well, not sure if anything's changed since then.
There was a pretty widespread crackdown on widevine decryption keys last year, iirc. That's the sort of thing you'd be looking for if you wanted to continue searching out other tools or possibly roll your own.