When the QIF file is created, switch to Banktivity and import created QIF file. Before importing a QIF file make sure to backup your data. To import a QIF file, select 'File' - 'Import transactions'. Then click 'Import File' and select created QIF file.
Select a Quicken account to import. And click 'Continue' button.
Then click 'Continue' button.
Pay attention that Account name must match what you have in Quicken. Because Quicken imports directly in that account without asking anything. And if you don't have account specified on the QIF file this account will be automatically created. Now your transactions are imported. You can categorize, review, delete them. They are already inside Quicken. Review transaction after import.