hide chat for mobile

Hello experts

I am really struggling for the last couple of days but no luck, I want to disable chat for mobile users, I tried putting the below code in my footer.php but its not working.
can you please advise what code I need to put and where exactly ?
I see two footer.php, one is in my theme/footer.php and other is theme/templates/footer.php I tried putting in both but no luck. here is the link to my page.

below is the code I tried. thanks.

script type=”text/javascript”>
var ua = navigator.userAgent.toLowerCase(),
platform = navigator.platform.toLowerCase();
platformName = ua.match(/ip(?:ad|od|hone)/) ? ‘ios’ : (ua.match(/(?:webos|android)/) || platform.match(/mac|win|linux/) || [‘other’])[0],
isMobile = /ios|android|webos/.test(platformName);
if (!isMobile) {
//place your live chat code here without the <script> tags
}
</script>