Help needed with extracting the audio from an iOS app - SLRPNK

Hello, I’m trying to get the downloaded audio out of an iOS app, but I struggle because the information I can find is mostly rather old, needs some additional software I need to pay for, etc. The content is downloaded post installing the app, so simply accessing the IPA doesn’t help. I have this app called naturespace (see naturespace.org [http://naturespace.org]), it’s an app that has really good recordings of rain, thunderstorms, etc. In my opinion those recordings are far better than anything I’ve heard so far. Now, I did pay for the content, but the app hasn’t been updated for years now, and there’s also been no new content for years as well. I wrote to the owners but didn’t get any response. I guess you could consider it abandoned at this point. Since I fear that anytime soon the app stops working, I’d like to save that content. I’m a bit tech savvy, I can work with CLI and such, but I’m not a professional coder or hacker, any help is appreciated.