Consumers' credit card payments with 3D Secure can never be reversed through a so-called 'chargeback' based on the reason 'it wasn't me'.
A payment up to 30 euros may be processed without mandatory authentication, which will increase your conversion. If you choose this option and a chargeback occurs with fraud as the reason, you will be liable for the costs.
Challenge & frictionless
When an authentication is performed in a frictionless flow, browser information is used to identify the payer. This can result in a payment without additional questions. If this is not successful, an authentication step (challenge) will follow. In most cases, a pop-up will appear to perform a confirmation in an app. Of course, the frictionless flow ensures higher conversion.