I just tried installing Parole on my own KDE Plasma+Wayland system and it just works, aside from opening an external playback window, which feels a bit weird, but I'm assuming it's normal. The only display drivers available are X, but the "Automatic" pick works.
If it doesn't work for you, make sure xwayland is installed.
Could you describe the issue in more detail, then? What happens when you try to play a video? If you get any error messages, please copy them.
It might not be Wayland-related at all.