Board Thread:Questions and Answers/@comment-97.64.173.28-20150526154919/@comment-24659969-20190902120944

Gameboy1009 wrote: How do you use them? As of now, you can't. The serial code or reference code input feature in-game been removed a long time ago. Old codes already expired anyway.

It is exchanged with direct granting feature instead. If you obtained any code or such thing during events or by buying products etc. Simply provide your account ID to PONOS (the ID number and texts on left top of title screen). Either thru email or as instructed or during offline events.

For the units available from the old serial codes itself, they are now obtainable in-game by clearing certain requirement(s). Visit the related unit page for the unlocking info.