Execute the following command to update a server

```sudo apt update && sudo apt upgrade```

Now, install the unattended upgrade on your Ubuntu system through the following command:

```sudo apt install unattended-upgrades apt-listchanges bsd-mailx```

After that, turn on the unattended security updates by running the following command:

```sudo dpkg-reconfigure -plow unattended-upgrades```

After executing the command, configure the automatic update by executing the command given below:

```sudo vi /etc/apt/apt.conf.d/50unattended-upgrades```

Now, you can set up the alert email ID by the below command:

```Unattended-Upgrade::Mail "xyz@abc.com";```

In the above command, you can write your email ID instead of “xyz@abc.com”. In case you want automatically reboot the Ubuntu box without confirmation for the Kernel update, then use the following command:

```Unattended-Upgrade::Automatic-Reboot "true";```

Finally, you can edit the /etc/apt/listchanges.conf and set up the email ID:

```email_address=xyz@abc.com```

You can verify that the setup is working by executing the below command:

```sudo unattended-upgrades --dry-run```

The software updater in Ubuntu will also give you update when available. You only need to click on the update option, and the package will be automatically upgraded to a newer version