A BURST Gift card is an awesome thing, It can be used for new orders with BURST and even to cover the cost of BURST subscription items or if you are lucky enough to have one or even several cards then you can redeem these and they will remain on your account as a Gift Card balance
You can apply your BURST Gift card balance as a payment method on your BURST account.
You can do this by logging into your BURST account and then going to your account through the person icon if you are on a laptop and the menu if you are on a mobile.
Once logged in go to the payment methods tab, Here is a quick link to get you there a little quicker: https://www.burstoralcare.com/user/payment-methods
Once there you will select the option to add a new payment method, Then select the Gift Card option.
From here you can key in your unique Gift Card code and select apply and you will see the Gift Card balance apply to your account.
This will be visible in the Payment Method section, Here is what you will see once it has been added:
Here is a super handy video to follow, This shows the redemption of a Gift Card from start to finish: