A bit more context:
In the 2.7 version, we have fully removed the web installer, replacing it with a command-line installer instead. This should address some of the common timeout errors reported during the installation process in previous releases.
The tools:install task is that new CLI installer - it's documented separately in 2.7
so if needed, users can run it again outside of the full installation process. As you may have guessed by now, this task doesn't exist in 2.6; hence the error.
There is still a section in the 2.7 documentation to install Nginx
. However, we've altered the order of operations, in part to try to prevent a common user error of visiting the web application in the browser before the installation process is fully completed (and thereby sometimes leading to incomplete installations). For 2.7, all previous installation steps have been tested and should work as expected with this change.
As José has noted, you may run into unexpected issues if you attempt to use Ubuntu 20.04 and PHP 7.4 with AtoM 2.6! We version the documentation per major release so that we can provide tested and trusted instructions for each one separately, and recommend following them.