I am developing one html page, in which I want the user to select multiple files from multiple folders. Also, I am using bootstrap 3 I didn't find any documentation in bootstrap to do so :

<div class="form1">
  <label for="input-folder-3">Select folders</label>
  <div class="file-loading">
  <input id="input-folder-3" name="input-folder-3[]" type="file" multiple><br/>
  <input class="mt-3" type="submit" value="Ok" id="submit">
</div>

<script>
   $(document).ready(function() {
    $("#input-folder-3").fileinput({
      uploadUrl: "/file-upload-batch/2",
      hideThumbnailContent: true // hide image, pdf, text or other content in the thumbnail 
       preview
     });
 });
</script>

I have tried this, but this is not working