Unable to run database updates via Drush - Call to undefined function batch_get()
Run your drush statement with the --debug flag, you will see something along the lines of:

Checking DB credentials yielded error: Unable to find a matching SQL     [debug]
Class. Drush cannot find your database connection details. 

Try navigating to the actual sites folder e.g. /var/www/vhosts/EXAMPLE/website/sites/default and run the drush command from the site specific directory.