How to Hide the "WP Remote Users Sync" Admin Menu

function plt_hide_wp_remote_users_sync_menus() {
	//Hide the "Settings → WP Remote Users Sync" menu.
	remove_submenu_page('options-general.php', 'wprus');
}

add_action('admin_menu', 'plt_hide_wp_remote_users_sync_menus', 11);

Where do I put this code?