WordPress Block – add_rewrite_rule doesn´t work

I created a WordPress Plugin to display Events.

The plugin is developed via WordPress Block and works fine. The url to the detail page is http://localhost:4444/?slug=02-12-2024_artist_name

To make it better readable, the url should look like http://localhost:4444/event/02-12-2024_artist_name

I added this code to my plugin.php script

add_action('init',  function () {
    add_rewrite_rule('event/([a-z0-9-]+)[/]?$', 'index.php?slug=$matches[1]', 'top');
    add_rewrite_tag('%slug%', '([^&]+)');
    error_log("Rewrite rules added");
});

add_filter('query_vars', function ($query_vars) {
    $query_vars[] = 'slug';
    return $query_vars;
});

But the rewrite doesn´t work correctely and i get a 404 “page not found”.

I tried to implement the render.php a second time (first time is via block.json), but I think it´s not the right way, cause I didn´t get my attributes

add_filter('template_include', function ($template) {
    if (get_query_var('slug') == false || get_query_var('slug') == '') {
        require_once plugin_dir_path(__FILE__) . 'src/render.php';
        return $template;
    }
});