For technical reasons, the 2-factor authentication via app (SMART PIN) is not possible with ADAC credit cards. Please switch the authentication method for the setup at Outbank from SMART-PIN to SMS-TAN.
You will find this in the onlinebanking from ADAC here: "Authentifizierungsmethode ändern" under "Profilverwaltung".
After setting up the login in Outbank you can use SMART-PIN again.