Disable Automatic Updates on Ubuntu 20.04 Focal Fossa Linux

Open and edit the /etc/apt/apt.conf.d/20auto-upgrades using the bellow command:

$ sudoedit /etc/apt/apt.conf.d/20auto-upgrades

Change content:
FROM:

APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";

TO:

APT::Periodic::Update-Package-Lists "0";
APT::Periodic::Download-Upgradeable-Packages "0";
APT::Periodic::AutocleanInterval "0";
APT::Periodic::Unattended-Upgrade "1";

All done.