Warning: require_once(database.php): Failed to open stream: No such file or directory in /var/www/html/classes/SubscriptionManager.php on line 7

Fatal error: Uncaught Error: Failed opening required 'database.php' (include_path='.:/usr/local/lib/php') in /var/www/html/classes/SubscriptionManager.php:7 Stack trace: #0 /var/www/html/messages.php(9): require_once() #1 {main} thrown in /var/www/html/classes/SubscriptionManager.php on line 7