Problems with SOAP request. 'Access-Control-Allow-Origin'

I am having a problem while sending a SOAP request. I've researched this topic and see many posts here and elsewhere on the topic, but nothing that worked for me, or really solves the problem I am having. To be more specific on what I am trying to do, I am trying to access an API on the BrightSign network. Link to documentation here... I have tried executing my request through a javascript function in the html page with no luck. I get "no" Access-Control-Allow-Origin "" error every time. I installed an add-on that I saw as a fix to get around this, and while I didn't get the Access-Control-Allow-Origin error, I got a Code 200 error. My biggest problem with this is that I downloaded the SoapUI and requested there is a request. At the same time, I received a response! I tried to copy and paste the raw XML from SoapUI into my test page to no avail. I get the same errors every time. Any help on this would be greatly appreciated.

thank

Here is the code for my page that I am using:

function soap(){
            var xmlhttp = new XMLHttpRequest();
            xmlhttp.open('POST', 'https://api.brightsignnetwork.com/2014/12/SOAP/Basic/', true);

            // build SOAP request
            var sr =
                '<soapenv:Envelope xmlns:soap="https://api.brightsignnetwork.com/2014/12/SOAP/" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">' +
                    '<soapenv:Header>' +
                        '<wsse:Security soapenv:mustUnderstand="1" xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">' +
                            '<wsse:UsernameToken wsu:Id="UsernameToken-541861B587A894A0A714970165483407">' +
                                '<wsse:Username></wsse:Username>' +
                                '<wsse:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText"></wsse:Password>' +
                                '<wsse:Nonce EncodingType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary">tlWiCWeD9E8JEaY00RfAhA==</wsse:Nonce>' +
                                '<wsu:Created>2017-06-09T13:55:48.340Z</wsu:Created>' +
                            '</wsse:UsernameToken>' +
                        '</wsse:Security>' +
                    '</soapenv:Header>' +
                    '<soapenv:Body>' +
                        '<soap:GetDynamicPlaylistByName>' +
                            '<soap:name></soap:name>' +
                            '<soap:loadContent></soap:loadContent>' +
                        '</soap:GetDynamicPlaylistByName>' +
                    '</soapenv:Body>' +
                '</soapenv:Envelope>';

        xmlhttp.onreadystatechange = function () {
            if (xmlhttp.readyState == 4) {
                if (xmlhttp.status == 200) {
                    alert('REQUEST SENT. CHECK FOR RESPONSE.');
                }
            }
        }

        // Send the POST request
        xmlhttp.setRequestHeader('Content-Type', 'text/xml');
        xmlhttp.setRequestHeader('Authentication-Type', 'Preemptive');
        xmlhttp.send(sr);
        }