The Confirm your Bank Account pop up is showing up in case you want to make a withdraw in a bank account that was not previously used in your Konto.com account. This is an extra layer of protection for your funds.
Therefore, before withdrawing your funds in the Bank account, you will have to first confirm your Bank account by making a deposit of minimum 3 EUR. After that you will be able to withdraw the full amount, including the confirmation transaction.
To learn how to withdraw your funds in a bank account click here.