Why is there an error in soap request 'not valid method'?

Question

PHP

Good afternoon. The question may seem childish to people who work closely with web services, but I'm in the process of learning and decided to understand the basic principles of working with SOAP through php.
here is the full content of the error: Fatal error: Uncaught SoapFault exception: [Client] Function ("getStock") is not a valid method for this service in E:\servNew\OSPanel\domains\test-soap\index.php on line 8
here my server:

<?php 

function getStock($id) {
  $stock = [
    '1' => 100,
    '2' => 200,
    '3' => 300,
    '4' => 400,
  ];

  $quantity = $stock[$id];
  return $quantity;
}

ini_set('soap.wsdl_cache_enabled', '0');
$server = new SoapServer( 'test.wsdl' );
$server->addFunction('getStock');
$server->handle();

?>

here is the client:

<?php 

$client = new 
    SoapClient( 
        "test.wsdl" 
    ); 

$client->getStock('1'); 

?>

wsdl file:

<?xml version ='1.0' encoding ='UTF-8' ?> 
<definitions name='Stock' 
 targetNamespace='http://example.org/StockQuote' 
 xmlns:tns=' http://example.org/StockQuote ' 
 xmlns:soap='http://schemas.xmlsoap.org/wsdl/soap/' 
 xmlns:xsd='http://www.w3.org/2001/XMLSchema' 
 xmlns:soapenc='http://schemas.xmlsoap.org/soap/encoding/' 
 xmlns:wsdl='http://schemas.xmlsoap.org/wsdl/' 
 xmlns='http://schemas.xmlsoap.org/wsdl/'> 

<message name='getStockRequest'>
  <part name='id' type='xsd:string'/>
</message>

<message name='getStockResponse'>
  <part name='Result' type='xsd:integer'/>
</message>

<portType name='StockPortType'>
  <operation name='getStock'>
    <input message='tns:getStockRequest'/>
    <output message='tns:getStockResponse'/>
  <operation>
<portType>

<binding name='StockBinding' type='tns:StockPortType'>
  <soap:binding style='rpc' transport='http://schemas.xmlsoap.org/soap/http'/>
  <operation name='getStock' />
<binding>

<service name='StockService'>
  <port name='StockPort' binding='StockBinding'>
    <soap:address location='test.wsdl'/>
  <port>
</service>

</definitions>

Answer 1

A SoapFault exception will be thrown if the wsdl URI cannot be loaded.

Obviously the client is expecting an absolute/full url.