Realraum UI requires JavaScript to be enabled in order to function properly, as it's written in Rust, and needs WebAssembly to run. Please enable JavaScript and reload the page.
Realraum UI is free/libre, open-source software, and licensed under the AGPL license. See its source code here: https://github.com/realraum/realraum-frontend
Alternatively, you can use the compat sounds view, which is HTML-only, and does neither require JavaScript nor WebAssembly; not even CSS (yikes!)