Consume external API using XmlHttp Request - Javascript

       var request = new XMLHttpRequest();
        var url = 'https://<domain>/api/Emp?extQuoteId=' + quoteId + '&RecId=' + recordId + '&customerId=' + customerId;

        request.open('GET', url, true);
        request.onload = function () {
         
            //var data = JSON.parse(this.response);    
        }
        request.send();