How to deactivate on mobile devices?

Hi fox-didl,
The plugin does not support this at the moment, however you can use this on your theme instead.

<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>

Hope that helps!

After adding this code into functions I can’t login anymore into wordpress /wp-admin. Any idea why?

This solutions would be very nice if working.

I think you did it wrong. Its javascript code, you should add it to your footer.php file, not functions.php.