I was a unity user back when the Unity Desktop Environment was still a thing in Ubuntu. I liked the feature that when I press the alt key by itself, I could get a search bar used to search in the application menubar. This feature is called HUD (Head Up Display). I use the global menu widget under my KDE install, and I wonder if there is a way to search inside menu just like in Unity. Thanks for trying to help out.
Currently, my only way is to
sudo apt install unity -y, which is not an alternative.