Seems like you forgot to load the text domain

The plugin handbook says that:

You need to load the MO file with your plugin’s translations. You can
load them by calling the function
load_plugin_textdomain()
(and
load_muplugin_textdomain()
if your plugin will be used as a Must-Use plugin). This call loads
{text-domain}-{locale}.mo from your plugin’s base directory.

So based on the example there, you could add this to your main plugin file (test.php):

function test_load_plugin_textdomain() {
    load_plugin_textdomain( 'test', false, basename( __DIR__ ) . '/languages/' );
}
add_action( 'plugins_loaded', 'test_load_plugin_textdomain' );