使用admin-ajax.php的AJAX请求

I'm trying to do an AJAX request in an WordPress plugin. The request is initiated on the front page embedded in an article using a custom shortcode.

I tried to combine infos from the documentation and this tutorial.

However something is going wrong when testing that method... the AJAX query hook isn't called.

This is how my page.php script is called for short code delivery:

add_shortcode('testshortcode', 'TestShortCodeFunction');

function TestShortCodeFunction($attributes)
{
   ob_start();
   include(__DIR__.'/page.php');
   return ob_get_clean();
}

This is my compacted test script page.php:

<?php

    add_action('wp_ajax_test', 'Test');
    add_action('wp_ajax_nopriv_test', 'Test');

    // do_action('wp_ajax_nopriv_test'); this calls Test()

    function Test()
    {
        echo 'Hallo';
        die();
    }
?>

<script type='text/javascript'>

    jQuery(document).ready(function() {

        console.log("JS query started");

        // The following does not call test()
        jQuery.ajax({
            type: "POST",
            url: "http://127.0.0.1/wordpress/wp-admin/admin-ajax.php?action=test",
            success: function(data) {
                console.log("Query returned: "+data);
            }
        });

    });

</script>

Output on the console is:

JS query started
Query returned: 0 

The Test() function is never call according to the PHP debugger.

The admin-ajax.php is executed according to the network monitor (URL http://127.0.0.1/wordpress/wp-admin/admin-ajax.php?action=test) but returns 0.

Inside admin-ajax.php do_action('wp_ajax_test') is called according to the PHP debugger.