You need the following  data to synchronize your Postbank Login with Outbank:

• Postbank ID
• Onlinebanking password

Please use the same login data you use for the online banking login on the website.

Please note:

• Business accounts do have a profile with a profile-name. Business customers have to enter their Postbank ID incl. profile name (PostbankID#Profile) to add the login in Outbank. 
• In the Onlinebanking (Postbank website) there has to be set a limit for payments with financial software:
  "Einstellungen" > "Auftrags- und Kartenlimit" > "Auftragslimit" > "Auftragslimit ändern" 

You can also contact the Postbank support if you need further information for your HBCI / FinTS credentials.