$ sudo cat /etc/apt/apt.conf.d/20auto-upgrades

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

$ sudo cat /etc/apt/apt.conf.d/50unattended-upgrades

// Automatically upgrade packages from these (origin:archive) pairs
//
// Note that in Ubuntu security updates may pull in new dependencies
// from non-security sources (e.g. chromium). By allowing the release
// pocket these get automatically pulled in.
Unattended-Upgrade::Allowed-Origins {
　　　"${distro_id}:${distro_codename}";
　　　"${distro_id}:${distro_codename}-security";
　　　// Extended Security Maintenance; doesn't necessarily exist for
　　　// every release and this system may not have it installed, but if
　　　// available, the policy for updates is such that unattended-upgrades
　　　// should also install from here by default.
　　　"${distro_id}ESMApps:${distro_codename}-apps-security";
　　　"${distro_id}ESM:${distro_codename}-infra-security";
　　　//      "${distro_id}:${distro_codename}-updates";
　　　//      "${distro_id}:${distro_codename}-proposed";
　　　//      "${distro_id}:${distro_codename}-backports";
};

$ sudo vim /etc/apt/apt.conf.d/50unattended-upgrades

// Automatically reboot *WITHOUT CONFIRMATION* if
// the file /var/run/reboot-required is found after the upgrade
Unattended-Upgrade::Automatic-Reboot "true";

// If automatic reboot is enabled and needed, reboot at the specific
// time instead of immediately
// Default: "now"
Unattended-Upgrade::Automatic-Reboot-Time "03:00";

$ sudo systemctl restart unattended-upgrades