Is there diffrence between local and laravel run Javascript code?

I have this code that works good. I tested at my localhost and my server. I add this code into my Laravel project. but somehow this generateFields doesn't show up. I use excatly same js and css CDN. and I checked the .js file included at html sorce code. Could someone teach me what might be cause please?

Whole code

https://jsfiddle.net/blueink/ec15ytmq/20/

This container doesn't show up.

index.html

<div id="container">

</div>

app.js

generateFields: (fieldNumber) => {
      Array(fieldNumber).fill().map((v, i) => {
        const ref = i + 1;
        $('#container').append(
          `<div class="fieldContainer">
    <div class="btn-group">
      <input type="text" class="search" data-ref="${ref}" placeholder="type something" class="form-control" onkeypress="return event.keyCode!=13" />
      <span class="search-clear glyphicon glyphicon-remove-circle" data-ref="${ref}"></span>
    </div>
    <ul class="list-group resultUl" data-ref="${ref}"></ul>
    </div>`
        )
      });
    },

via Chebli Mohamed