Hi suffering
I fixed it
Below is the code to use at the end of footer.php file
<!-- BACK TOP TOP BUTTON -->
<div id="back-to-top" data-spy="affix" data-offset-top="200" class="back-to-top hidden-xs hidden-sm affix-top">
<button class="btn btn-primary" title="Back to Top"><i class="icon-arrow-up fa fa-angle-double-up"></i></button>
</div>
<script type="text/javascript">
(function($) {
// Back to top
$('#back-to-top').on('click', function(){
$("html, body").animate({scrollTop: 0}, 500);
return false;
});
})(jQuery);
</script>
<noscript>
<?php echo JText::_('YOU MUST ENABLED JS'); ?>
</noscript>
<!-- BACK TO TOP BUTTON -->
Regards