fetch json output

{
    "records": [
        {
            "id": "3",
            "Name": "Jana Müller",
            "Premium": "1",
            "Aktiv": "1",
            "Gender": "W"
        }
    ]
}

var kundeParam = 'api.php?kunde=';
    var HttpClient = function() {
        this.get = function(kundeParam, aCallback) {
        var anHttpRequest = new XMLHttpRequest();
            anHttpRequest.onreadystatechange = function() { 
                if (anHttpRequest.readyState == 4 && anHttpRequest.status == 200)
                    aCallback(anHttpRequest.responseText);
                }

                anHttpRequest.open( "GET", kundeParam, true );            
                anHttpRequest.send( null );
            }
        }

                var btn2 = document.getElementById('data_x');
                
                btn2.addEventListener('click', function() {
                    
                var urldata = document.getElementById('kunde-data').value;
                    
                var client = new HttpClient();
                
                client.get(kundeParam + urldata, function(response) {
                    // Wie kann ich hier was anzeigen lassen bzw den Premium Status ob der Aktiv (1) oder UnAktiv (0) ist?
                });