How to Hide FooBar WordPress Notifications Admin Menus

function plt_hide_foobar_notifications_lite_menus() {
	//Hide "FooBar".
	remove_menu_page('edit.php?post_type=foobar_notification');
	//Hide "FooBar → Notifications".
	remove_submenu_page('edit.php?post_type=foobar_notification', 'edit.php?post_type=foobar_notification');
	//Hide "FooBar → Add New Notification".
	remove_submenu_page('edit.php?post_type=foobar_notification', 'post-new.php?post_type=foobar_notification');
	//Hide "FooBar → Help".
	remove_submenu_page('edit.php?post_type=foobar_notification', 'foobar-help');
	//Hide "FooBar → Settings".
	remove_submenu_page('edit.php?post_type=foobar_notification', 'foobar-settings');
	//Hide "FooBar → Upgrade".
	remove_submenu_page('edit.php?post_type=foobar_notification', 'foobar-notifications-lite-pricing');
}

add_action('admin_menu', 'plt_hide_foobar_notifications_lite_menus', 1000000000);

Where do I put this code?