How do I...

Maybe I'm retarded, but I can't find a way how to use a theme I made in KLCK. I made a simple one just a few elements but there's no way to use it. And I can't really find instruction anywhere. Is there a trick for that? I can export it, okay, but I browsed all the options and... nothing, really.

Click the icon that looks like a floppy disc along the top, just right off center. This applies your work as your current wallpaper.

I've done that many times, but the project I just saved doesn't become my wallpaper. What am I doing wrong. I'm on my Note8