Can't understand custom post ype rewrite rule!

Hi everyone! I’m trying to transorm this

https://localhost/wp_pluginDev/?post_type=corso

in

https://localhost/wp_pluginDev/corsi/.

This is the code I used to register my custom post type:

function corso_register() {

	$labels = array(
		'name' => 'Corsi',
		'singular_name' => 'Corso',
		'add_new' => 'Aggiungi un corso',
		'add_new_item' => 'Aggiungi un corso',
		'edit_item' => 'Modiica il corso',
		'new_item' => 'Nuovo corso',
		'view_item' => 'Visualizza corso',
		'search_items' => 'Cerca corso',
		'not_found' =>  'Non ho trovato nulla',
		'not_found_in_trash' => 'Non ho trovato nulla nel cestino',
		'parent_item_colon' => ''
	);

	$args = array(
		'labels' => $labels,
		'public' => true,
		'publicly_queryable' => true,
		'show_ui' => true,
		'query_var' => true,
		'rewrite' => array(

			'slug' => 'corso',

		 ),
		'has_archive' => 'corsi',
		'capability_type' => 'post',
		'hierarchical' => false,
		'menu_position' => null,
		'supports' => array('title','editor','thumbnail')
	  ); 

	register_post_type( 'corso' , $args );

	global $wp_rewrite;
 	$wp_rewrite->flush_rules();
}

The ‘has_archive’ is set to ‘corsi’ so why it doesn’t work??Thank you for the help!

PS: I searched or old discussion but i couldn’t find nothing!