download ahcdn.php.txt and ahcdn_config.php.txt (links below) to /admin/cdn/ subfolder of KVS installation
rename ahcdn.php.txt to ahcdn.php , ahcdn_config.php.txt to ahcdn_config.php
fill with the proper data ahcdn_config.php
After that:
In the control panel of the KVS go to http://example.com/admin/servers.php open Local Videos (might be another storage server, depends on which server the files were imported, usually Local Videos)
Select Streaming type CDN
CDN control script (*) write ahcdn.php
Streaming key (*): does not matter , you can write any symbols