About Events in the JStree

I am using a jstree in a .net mvc5 application but when I load it with the root node closed and it does not show the child nodes, I have to double click to expand, as I can make it open by default in the first level, and that when a single click on a parent node opens, and not with 2 click ?? here my code.

       $(function () {

                $('#jstree').on("changed.jstree", function (e, data) {
                    window.location.href = data.node.a_attr.href;
                });

                tree.jstree("refresh");
                $('#jstree').jstree({
                    "core": {
                        "multiple": true,
                        "check_callback": false,
                        'themes': {
                            "responsive": true,
                            'variant': 'larg',
                            'stripes': false,
                            'dots': false
                        }
                    },
                    "types": {
                        "default": {
                            "icon": "fa fa-folder icon-state-warning icon-lg"
                        },
                        "file": {
                          "icon": "fa fa-file icon-state-warning icon-lg"
                        }
                    },
                    "plugins": ["dnd", "state", "types", "sort"]
                });
            });
        </script>