Before updating your version of Moodle, make sure that the server requirements are met on your MoodleBox. To do this, log in to Moodle, visit Site Administration > Server > Environment, click on Update component, then check that no line says Check in red.
Warning site not https is not a problem and can be ignored.
To update Moodle, perform the following operations, using the command line.
Update to a minor version
To update to the next minor version of Moodle (4.1.1, 4.1.2, etc.), type the following commands in the terminal:1
cd /var/www/moodle/ sudo -u www-data -g moodlebox git pull
Update to a major version
To update to the next major version of Moodle (4.1, 4.22, etc.), type the commands above, then the additional following commands, indicating the adequate branch, e.g.
sudo -u www-data -g moodlebox git config remote.origin.fetch "+refs/heads/*:refs/remotes/origin/*" sudo -u www-data -g moodlebox git fetch origin sudo -u www-data -g moodlebox git checkout MOODLE_401_STABLE