The Roblox gift card is the currency used in the Roblox platform, you can top up your balance in the game and through it you can subscribe to the premium subscriptions available on the platform
1- Make sure to log in to your Roblox account that you want to redeem the code for.
2- Go to the redeem promo page.
3- Enter the code which you received on your iCards inbox.
4- Click Redeem.