肥皂错误：“看起来我们没有XML文档”

I check the difference bettwen a call who work simulating soap with curl request which work here is the xml that work:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ser="http://service.test.com/">
    <soapenv:Header/>
    <soapenv:Body>
        <ser:DoItdoItRequest1>
            <version>1.0</version>
        </ser:DoItdoItRequest1>
    </soapenv:Body>
</soapenv:Envelope>

I change my code using SoapClient to be more clean than emulating a curl request, but my server return me:

looks like we got no XML document

When debugging I get from client->__getLastRequest()

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="http://service.test.com/">
    <SOAP-ENV:Body>
        <ns1:DoItdoItRequest1>
            <version>1.0</version>
        </ns1:DoItdoItRequest1>
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

The only difference seems to be:

<ser:DoItdoItRequest1>

against

<ns1:DoItdoItRequest1>

Do you know how to change this ns1: to a ser: with SoapClient ? an option maybe ? I can't find helpful help about that...

Regards.