First call: query your account balance

<?php
include('nusoap/nusoap.php');

$client = new soapclient('http://www.mdworks.info/_soap/control.php');
$params = ['login' => 'your_login', 'motdepasse' => 'your_password'];

$quota = $client->call('Recup_Credit', $params);

if ($client->fault) {
    die("SOAP error: {$client->faultstring}");
}

echo "Available quota: {$quota}\n";

<?php
try {
    $client = new SoapClient(null, [
        'location' => 'https://www.mdworks.info/_soap/control.php',
        'uri'      => 'https://www.mdworks.info',
        'encoding' => 'ISO-8859-1',
    ]);

    $quota = $client->Recup_Credit('your_login', 'your_password');

    echo "Available quota: {$quota}\n";
} catch (SoapFault $fault) {
    trigger_error("SOAP Fault: ({$fault->faultcode}) {$fault->faultstring}", E_USER_ERROR);
}

curl -X POST https://www.mdworks.info/_soap/control.php \
  -H 'Content-Type: text/xml; charset=utf-8' \
  -H 'SOAPAction: ""' \
  -d '<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
  <SOAP-ENV:Body>
    <Recup_Credit>
      <login>your_login</login>
      <motdepasse>your_password</motdepasse>
    </Recup_Credit>
  </SOAP-ENV:Body>
</SOAP-ENV:Envelope>'

from zeep import Client

client = Client('http://www.mdworks.info/_soap/control.php?wsdl')
quota = client.service.Recup_Credit(
    login='your_login',
    motdepasse='your_password',
)

print(f'Available quota: {quota}')

import axios from 'axios';

const envelope = `<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
  <SOAP-ENV:Body>
    <Recup_Credit>
      <login>your_login</login>
      <motdepasse>your_password</motdepasse>
    </Recup_Credit>
  </SOAP-ENV:Body>
</SOAP-ENV:Envelope>`;

const { data } = await axios.post(
  'https://www.mdworks.info/_soap/control.php',
  envelope,
  { headers: { 'Content-Type': 'text/xml; charset=utf-8' } },
);
console.log('Quota:', data);