Check the inbox of the email address used for purchase; ArKaos sends a copy of the code there.
When searching for "ArKaos GrandVJ 1.6.5 activation code link," the results are often filled with "Keygens," "Cracks," or "Serial Generators." Here is why you should avoid them:
Finding a "crack" or a free activation code for high-end professional software like (the current version, as 1.6.5 is legacy) is a common search, but it’s a path that usually leads to more trouble than it's worth.
Cracked versions of GrandVJ are notoriously unstable. In a live environment, the last thing you want is a "License Error" popup or a hard crash while the music is pumping.
If you’re looking to use legally, here are your best options: