The automatic upgrade can be done from System > Firmware.
If an update is found the buttons will change to allow you to Download and Update the firmware.
Click on the Download and Upgrade button. A prompt will be displayed advising to download the Current Active Configuration. Please click on the underlined download text. After downloading the current config click the Ok button to start the upgrade process.
The router will download and then apply the firmware. The time that this process takes will depend on your internet connection’s speed.
The firmware will now be applied to the router*. The amount of time it takes for the firmware to upgrade will also depend on the router that’s being upgraded.
*Upgrading the firmware will cause the router to reboot.