How to add NTLM authorization to my soap request using easy-soap-request npm package

Question

i using easy-soap-request for my soap request, i want to add NTLM authorization to my soap request.

I try to add Authorization in my header

const headers = {
    'Content-Type': 'application/soap+xml;charset=UTF-8',
    'soapAction': 'https://wsiautor.uni-login.dk/hentDataAftaler',
    'Authorization: 'Basic ' + Buffer.from("username:password").toString('base64')
};

But it didn't work

My code:

const url = 'https://wsiautor.uni-login.dk/wsiautor-v4/ws';
const headers = {
    'Content-Type': 'application/soap+xml;charset=UTF-8',
    'soapAction': 'https://wsiautor.uni-login.dk/hentDataAftaler',
};
// example data
const xml = `
<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:uni="https://uni-login.dk">
   <soap:Header/>
   <soap:Body>
      <uni:hentDataAftaler>
         <uni:wsBrugerid>?</uni:wsBrugerid>
         <uni:wsPassword>?</uni:wsPassword>
      </uni:hentDataAftaler>
   </soap:Body>
</soap:Envelope>
`;


// usage of module
soapRequest({url: url, headers: headers, xml: xml}).then(({response: {body, statusCode}}) => {
    console.log(body);
    console.log(statusCode);
}).catch((errorBody) => {
    console.error(errorBody);
}); 

Thank you For your Help