Retrieve file column and display PDF in iframe

webapi.safeAjax({
    type: "GET",
    url: "/_api/msevtmgt_events({{ request.params.id }})/musdyn_brochure",
    contentType:"application/json",
    success: function(res) {
        console.log(res);
        $('#main').append('<iframe src="data:application/pdf;base64,' + res.value + '" frameborder="0" height="100%" width="100%"></iframe>');
    },
    error: function(xhr, status, error){
        var errorMessage = xhr.status + ': ' + xhr.statusText;
        console.log(errorMessage);
    }
});