How to pass NTLM Authentication to an AJAX call with REST API

When posting a document to CS with REST API, how can I pass NTLM authentication to REST when making an ajax call for users?

For testing we're using 'admin' username/password to handle the authentication (see example below) and post documents, ideally we would like to use the current user's credentials to handle the authentication call.

Please note not using AppWorks, this is mainly for a html page within content server, nor do we use OTDS instead we use CSDS.

function authenticate() {

$.ajax({
    type: "POST",
    url:  baseApiURL + "/v1/auth",
    data: { username: "Admin", password: "Password" }
}).done(function(data) {
    otcsTicket = data.ticket;
}).fail(function(request, statusText, statusMessage) {
    // ...failed
});

};

Many thanks,
Alban