Laravel + Vue + Axios - Store data

I'm trying to store data with axios, but I can't make it..

this is my View

var config = {
  headers: {'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')}
};
  var app = new Vue({
          el: '#app',
          data: {
            isCardModalActive: false,
            name: null,
            email: null,
            message : 'oi',
            video_url: '',
            video_title: '',
            video_id: '',
            username: '',
            user_id: '1' 
          },
          methods: {
            onSubmit(message) {              
            axios.post('', {message: 'Test', round: '1', video_id: '31',username: '4'   }, config)
              .then(function(response){
                console.log(response)
              });  
            },
            saveName: function(e) {
              if(this.name && this.email) 
              {
                var mod = document.getElementById('reg-modal');
                mod.className += ' animate-modal';
              } 
              else
              {
                alert('Please fill up your name and Email');
                e.preventDefault();
              }
            }
          }
        });

and here my Controller:

 $comment = new Comments;
    $comment->message = $request->message;
    $comment->round = $request->round;
    $comment->video_id = $request->video_id;
    $guest_name = $request->username;
    $comment->user_id = $request->username;
    if(!is_numeric($guest_name) && $guest_name != null){
        $comment->user_id = -1;
        $comment->guest_name = $guest_name;
    } else {
    }
    $comment->save();
    return response()->json($comment);

When I click to store the response is {data: {…}, status: 200, statusText: "OK", headers: {…}, config: {…}, …}

But nothing happens, what am I missing?

via Chebli Mohamed