To redeem your BETA code, turn on your PlayStation 4 and do the following : Go to [Settings] > [PlayStation Network] > [Account Information] > [Wallet] > [Add Funds] and press X Select [Redeem Code] Carefully enter the code and select ‘Continue’.
Please note that the BETA will be live from June 8 to June 12. Also note that your code will not work until the BETA starts on June 8.