Your Virta account balance is automatically topped up when the balance is less than 10 euros. When starting a charging session with an account balance of less than 10 euros, a 30 euro topup is transferred from your payment card to your Virta account. Please note that in order for the topup to work there must be a valid payment card linked to your Virta account.
You can also manually add account balance through the customer portal. Log in to the customer portal with your credentials and on the main page you will see a button for adding balance. You can choose the desired amount and proceed after which the amount is transferred from your payment card to your Virta account.