I can never quite remember how I like my unattended upgrades configured on my Raspberry Pi’s so I’m just popping it here. It should work for all versions!
nano /etc/apt/apt.conf.d/50unattended-upgrades
Unattended-Upgrade::Origins-Pattern { "origin=Raspbian,codename=${distro_codename},label=Raspbian"; "origin=Raspberry Pi Foundation,codename=${distro_codename},label=Raspberry Pi Foundation"; }; Unattended-Upgrade::Automatic-Reboot "true"; Unattended-Upgrade::Automatic-Reboot-Time "02:00";
To check it:
unattended-upgrade --dry-run
Logs can be found at:
/var/log/unattended-upgrades/unattended-upgrades.log and /var/log/unattended-upgrades/unattended-upgrades-dpkg.log