Fatal error: Uncaught MongoDB\Driver\Exception\ConnectionTimeoutException: No suitable servers found (`serverSelectionTryOnce` set): [connection refused calling hello on 'localhost:27017'] in /var/www/html/mongodb/vendor/mongodb/mongodb/src/functions.php:487
Stack trace:
#0 /var/www/html/mongodb/vendor/mongodb/mongodb/src/functions.php(487): MongoDB\Driver\Manager->selectServer()
#1 /var/www/html/mongodb/vendor/mongodb/mongodb/src/Collection.php(687): MongoDB\select_server()
#2 /var/www/html/templates/encabezado.php(27): MongoDB\Collection->findOne()
#3 /var/www/html/index.php(11): include('...')
#4 {main}
thrown in /var/www/html/mongodb/vendor/mongodb/mongodb/src/functions.php on line 487