DeDRM Readium epub

Hey community

I found a really nice app that provides ebooks, but they are DRM protected by Readium. I've installed it in an Android Emulator and inspected the traffic so that's how I've found out it's Readium.

I found this project [1] but I think I need a decryption passphrase which I don't know how to get it. I can show relevant requests made by the app if someone could help me.

I would like to be able to remove the DRM from these books so I can share them on zlib.

Any help is much appreciated.

[1] https://notabug.org/NewsGuyTor/DeDRM_tools-LCP/src/master/CALIBRE_CLI_INSTRUCTIONS.md