If you are building a new application or have the ability to refactor your code, The best long-term solution is to abandon the native extension entirely.

// xmlrpc_shim.php – drop-in replacement for ext-xmlrpc if (!function_exists('xmlrpc_encode_request')) function xmlrpc_encode_request($method, $params, $output_options = []) $encoder = new \PhpXmlRpc\Builder\ValueBuilder(); $xml = '<?xml version="1.0"?><methodCall><methodName>' . $method . '</methodName><params>'; foreach ($params as $param) $xml .= '<param>' . $encoder->buildXml($param) . '</param>';

of how to transition your project to a pure-PHP alternative like the Enable XML-RPC on Xampp - php - Stack Overflow 4 Jan 2021 —