You can easily redeem your eVoucher to Account Credit by entering the unique code at the Redeem eVoucher page. You can also access this through your Kogan.com Account.
If you are not signed in to your Kogan.com Account at the time, you will be prompted to sign in before proceeding to the Redeem eVoucher page.
If you do not have a Kogan.com Account, you can create one here, by clicking the 'Sign In or Sign Up' button.
In order to use your credit, you will need to apply the available "Account Credit" as a payment method at checkout. You can then pay any remaining balance via another payment method.