No widgets in kde plasma?

I was surprised that I couldn’t change the background and learned that I need to place an image at, I believe, $HOME/.bacground-image or something like that. I haven’t tried yet because, since I need it to be per activity, I need to figure that out first.

Anyway, I tried to add the Activity Switcher but when I right click and select Add Widgets nothing happens.

Is there some other package I need to install? Would this work better somehow if I used Home Manager, which I intend to but haven’t yet?

Thanks in advance,

I don’t really understand but both the widget functionality and the ability to change wallpaper are avilable to me now. I’m not entirely sure when it started working. All I did kde-related was enable the kde-connect program. I also switched at some point to the development channel. Could that be the difference.

I’m happy of course that it’s working, but I don’t like mystery in my OSs, so I’d like to understand why.