<div id="fileManager"></div>
<script>
    var baseUrl = "https://demos.telerik.com/service/v2/core/filemanager/";

    $("#fileManager").kendoFileManager({
        toolbar: {
            items: [
                { 
                    name: "custom", 
                    text: "Custom",
                    click: function() {
                        alert("Custom button clicked");
                    }
                }
            ]
        },
        dataSource: {
            transport: {
                read: {
                    method: "POST",
                    url: baseUrl + "Read"
                }
            }
        }
    });
</script>