This is not a support but a help question: Where have I put this:
“Please add the code below in current active theme’s functions.php file
This code will integrate BuddyPress profile URL with wpDiscuz. BuddyPress Display Names and Avatars will be integrated automatically.
As you already get answer you need to put it in functions.php file which is located in: wp-content/themes/agama-pro/functions.php
But since your modifications will be lost on every theme update you should switch to Agama Pro Child theme and add that code to child theme functions.php file which is located in (you need to install and activate child theme first): wp-content/themes/agama-pro_child/functions.php