$('#kt_docs_jstree_basic').jstree({
    "core" : {
        "themes" : {
            "responsive": false
        }
    },
    "types" : {
        "default" : {
            "icon" : "fa fa-folder"
        },
        "file" : {
            "icon" : "fa fa-file"
        }
    },
    "plugins": ["types"]
});
														
<div id="kt_docs_jstree_basic">
    <ul>
        <li>
            Root node 1
            <ul>
                <li data-jstree='{ "selected" : true }'>
                    <a href="javascript:;">
                        Initially selected </a>
                </li>
                <li data-jstree='{ "icon" : "flaticon2-gear text-success " }'>
                    custom icon URL
                </li>
                <li data-jstree='{ "opened" : true }'>
                    initially open
                    <ul>
                        <li data-jstree='{ "disabled" : true }'>
                            Disabled Node
                        </li>
                        <li data-jstree='{ "type" : "file" }'>
                            Another node
                        </li>
                    </ul>
                </li>
                <li data-jstree='{ "icon" : "flaticon2-rectangular text-danger" }'>
                    Custom icon class (bootstrap)
                </li>
            </ul>
        </li>
        <li data-jstree='{ "type" : "file" }'>
            <a href="http://www.keenthemes.com">
                Clickable link node </a>
        </li>
    </ul>
</div>