Magento CMS is installed manually (not from the Applications Catalog) on a website.
The following error is shown when trying to access it in the browser:
CONFIG_TEXT: Service Temporarily Unavailable
.maintenance.flag file exists in the
var subdirectory of the Magento installation.
Connect to the server via SSH and remove the
# rm -f /var/www/vhosts/example.com/var/.maintenance.flag
Note: To avoid such situations in the future, it is recommended to install Magento from the Applications Catalog: Domains > example.com > Applications > All Available Applications, find Magento and install it.