I am trying to put the site into Maintenance Mode using Drush.
I have tried this:
drush vset maintenance_mode 1 Command variable-set requires Drupal core version 6 or 7 to run. The drush command 'vset maintenance_mode 1' could not be executed.
drush sset system.maintenance_mode TRUE Command state-set requires Drupal core version 8+ to run. The drush command 'sset system.maintenance_mode TRUE' could not be executed.
I have looked through the output of the commands, but cannot find any reference to it. Is there a particular command for Backdrop to achieve this?