Go to the Roblox website or open the Roblox app
Sign in to your account
If you have a Roblox gift card, go to the Redeem page
Enter the gift card code
Click Redeem
If you have a Robux code from a promotion, enter it on the same redeem page
Confirm the redemption
Check your account balance for the Robux or credit
If the Robux does not appear, refresh the page or sign out and back in