dropzone csrf codeigniter

1var myDropzone = new Dropzone("div#mydropzone", {
2  url: "/controller/method_receive_files",
3  sending: function (file, xhr, formData) {
4    formData.append('<?php echo $this->security->get_csrf_token_name(); ?>', '<?php echo $this->security->get_csrf_hash(); ?>');
5  }
6}); 
7//OR...
8myDropzone.on('sending', function(file, xhr, formData) {
9  formData.append('<?php echo $this->security->get_csrf_token_name(); ?>', '<?php echo $this->security->get_csrf_hash(); ?>');
10});