I experienced the exact same thing. I wanted to record/stream the audio but I found it surprisingly difficult. The Java app is easy to use but much lower audio quality. The client side js heavily relies on the audio api of browsers and I couldn't get it working in nodejs. I don't know why this guy decided on his own audio codec for broadcasting amateur radio over the web. The only viable solution I found to be using an actual browser which is a pain in the ass. This guy is very weird. He wants to share amateur radio but makes it impossible to build off of.