Comment 2 for bug 1894208

Oh, one other thing to check on is whether you have a sound theme installed and enabled. This app expects some sound effects that belong to `sound-theme-freedesktop` (https://www.archlinux.org/packages/extra/any/sound-theme-freedesktop/). Because sound themes never really took off, that might be a risky assumption. (To be sure, gnome-tweaks has a sound theme option under Appearance, or it's in dconf under `/org/gnome/desktop/sound`). The reference flatpak manifest for the newest version includes the sound theme right there, but for a regular install to your system from source you may need to check on that.