Apple has announced that for the time being, they will not allow developers to access the Apple Card information (balance, transactions etc). Since Apple Card is issued by Goldman Sachs, and they do not have any customer front end (as Apple Card is their first consumer product), we're also unable to access it via Goldman Sachs too.
Fortunately, Apple recently introduced an "export statement" option, allowing customers to export the transactions in form of CSV and possibly other formats in the future. Here's how to do this:
Open the Wallet app on your iOS device.
Tap on our Apple Card.
Then tap on the "Card balance" label.
Access your monthly statement.
Select "Export Transactions".
This will open up a traditional iOS Share Sheet and you can select MoneyWiz as the destination or Numbers/Excel if you wish to modify the CSV file first. More information about importing in general can be found here. Please remember that prior to import, you need to create the account in MoneyWiz.
Of course, you can also continue to manage the account manually (like a cash account) by entering transactions manually in MoneyWiz as they happen.
Sadly there's still no word about more automated Online Banking support. If Apple ever allows developers access to its data, we'll integrate with it immediately.