By the way friends, I tried and installed lightly-kf5-git and lightly-kf6-git, the blur worked, but when I tried to edit the Plasma Style (as shown in the github tutorial), I got an error message and could not access the transparency settings.
So, Lightly is something like Kvantum, you must select the Plasma Style for it to work, otherwise it won’t work.
So what I’m looking for is not to depend on these packages, so I’ll keep looking for something to make blur or transparencies with Plasma default. I will try kwin scripts as suggested by one of our friends.
I will also keep reading in forums and so on, and will post a solution here when I have found it.