How to Hide the "Admin Protection" Admin Menu

function plt_hide_wp_admin_protection_menus() {
	//Hide the "Settings → Admin Protection" menu.
	remove_submenu_page('options-general.php', 'plgwpap_settings_page');
}

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

Where do I put this code?