Wordpress Ajax Call

ajax_func.php

add_action( 'wp_ajax_wordpress_ajax_action_name', 'wordpress_ajax_action_name' );
add_action( 'wp_ajax_nopriv_wordpress_ajax_action_name', 'wordpress_ajax_action_name' );

function wordpress_ajax_action_name(){
    echo 'test :)';
    wp_die();
}

functions.php

wp_enqueue_script( 'myscripts', get_stylesheet_directory_uri() . '/assets/js/app.min.js', array('jquery'), '1.0.0', true );
wp_localize_script( 'myscripts', 'ajaxurl', admin_url( 'admin-ajax.php' ) );

script.js

$( 'body' ).on( 'event_ajax', function(){

    jQuery.ajax({
        url: ajax_url,
        type: 'post',
        data: {
            action: 'wordpress_ajax_action_name',
        },

        success: function (response) {
            console.log(response);

        },
        error: function (errorThrown) {
            console.log(errorThrown);
        }
    });

} );

Where do we need to add ajaxurl?