Hw to migrate WP from test server to another hosting servder

Hi,
How can I move/migrate my WordPress site on our test server to another hosting server? I'm using duplicator plugin and while I followed through and downloaded the archive and the installer.php, to upload the archive and installer.php to the other hosting server via ftp is now an issue because the archive and installer.php seems not to be seen on the server. How can you aid me?