Exchange Codes are exclusive to the PC version of the game (Google Play Games, Steam).
※ Please note that they are not available on iOS, iPad OS, or Android.
How to redeem Exchange Codes:
1.) Open the in-game smartphone menu by selecting its icon on the bottom right of the screen.
2.) Select [Exchange Code] and enter the code.
Furthermore, please note that there are currently no active Exchange Codes at this time.