I can help you share information about exporting data into QBO, smosieur.
When you import data in QuickBooks Online, it will not create a double entry. If this is your first time importing data into QuickBooks, the system will automatically set up payroll accounts if you haven't set them up yet.
To set up the correct mapping and preferences when importing, you can follow the steps given in setup export of IOP data to QuickBooks Online (QBO).
Please let me know if you have any other exporting concerns. I'm here to assist.