If you want to import Apple Card transactions in QuickBooks Self-Employed, the system will require CSV files to during the import process. For QBO files, you will need to convert it so you can proceed with transferring the data over.
Once you have the spreadsheet ready, follow the steps below in your Self-Employed account:
Click the Gear icon and choose Imports.
Tap the import transactions link at the bottom for accounts not connected to QBSE.
Press Browse to find the CSV file of the bank entries.
After this, all the transactions will be listed at the bottom. Make sure to map the data correctly.
Hit Continue then Done.
I'm adding a few related articles below to guide you further with the process: