How to retrieve your Roblox account details:
Sign in to Roblox .
Confirm you are on the account where you want to redeem the voucher;
How to redeem:
Purchase the Roblox voucher and locate the code in your order confirmation or email;
Go to Log in to Roblox ;
Enter the code exactly as shown;
Confirm redemption;
For Robux credit, convert the balance if prompted, or for items, check your inventory.