stdClass Object
(
    [access_token] => G43wXXEdJanZAFiJHwhcyYLTVtvl
    [expires_in] => 3599
)
<br> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<script>
  function fetchdata(){
 $.ajax({
  url: 'fetch.php',
  type: 'post',
  success: function(response){
  }
 });
}

$(document).ready(function(response){
 setInterval(fetchdata(), 5000);
});
</script>