Trying to install CUDA 10.1: does exist a reliable manual?


It’s 2nd time that I install CUDA rather try to install it as for the moment it doesn’t work at all.
With 10.2 it worked, but 10.2 is incompatible with any of version of TensorFlow (further TF)… at least the manual on TF site claims that the latest version of TF (i.e. TF2.1.0 is compatible with CUDA 10.1, not CUDA 10.2.
I proceeded as explained on this link:
Download Installer for Linux Ubuntu 18.04 x86_64
After executing the last instruction I see this:
pavel@ALABAMA:~/installers$ ls
pavel@ALABAMA:~/installers$ sudo apt-get -y install cuda
Reading package lists… Done
Building dependency tree
Reading state information… Done
E: Unable to locate package cuda

What should I check in my system to resolve the problem ?