Support

There are two distinct update scenarios, and the answer differs for each.

Joomla's automatic update service works by registering your site with an external service running on Joomla's own servers. That remote service then triggers the update on your site. Since this is an external service with no integration with Akeeba Backup, it cannot take a backup before the update runs. This applies to any extension being updated this way, including Akeeba Backup itself.

If you want pre-update backups with automatic updates, you need a site management tool that supports this. Options include self-hosted solutions such as Akeeba Panopticon or YourSites, or commercial services such as mySites.guru or Watchful. All of these can take a backup before applying a Joomla update.

Manually updating Joomla core through the backend (System → Update → Joomla) is a different matter. For that specific operation, you can enable the Backup On Update plugin that ships with Akeeba Backup for Joomla. Once enabled, manually triggering a Joomla core update through the backend will cause Akeeba Backup to take a backup first. Instructions for enabling and configuring this plugin are in the documentation.

Note that this plugin covers Joomla core updates only. Updating Akeeba Backup itself, or any other extension, does not trigger an automatic backup under any circumstances.