How to Hide the "Address Autocomplete" Admin Menu

function plt_hide_postcode_eu_address_validation_menus() {
	//Hide the "Settings → Address Autocomplete" menu.
	remove_submenu_page('options-general.php', 'postcode-eu-address-validation');
}

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

Where do I put this code?