Currently Apple Card accounts are only accessible via the Apple Wallet app. Unfortunately, we cannot support mobile sites based with iOS access only as of now. Apple Card accounts would need to be updated manually in Banktivity until this changes. If Apple (or Goldman Sachs) decides to allow access to Apple Card account information online from a web browser application, we should then be able to add Direct Access support at that time.
2/11/20 UPDATE: Apple has added the ability to export statements from the Wallet app in CSV and/or OFX file format. Unfortunately, at the time of this update neither CSV nor OFX files exported from the Wallet app are working properly. The CSV files are coded so payments and charges are reversed. The OFX file is not adhering to the OFX specification and has many missing tags in the file which is resulting in a ‘No valid destination accounts’ message in Banktivity. Both issues have been brought to Apple’s attention and we hope they will make the necessary corrections soon.