I think this is general question about software installation in Ubuntu (20.04) and I don't understand some obvious things.
I need: "CMake 3.17 or higher is required". In repos and software app versions are older, so the only way I have found is to download and install it from the developers site. I succesfuly run
./configure
make
sudo make install
but there are still no package cmake in the system (like, after sudo apt-get install cmake). All the guides on packages installation stop at this step and don't mention what to do after you pass sudo make install. The repeat of this command is says that everythin is up to date.