Thank you for reaching out. You can add your PAYG Instalments to your BAS by following these steps:
Navigate to the GST tab
Select Settings in the top right
Choose Tax Settings
Ensure PAYGI is selected with the applicable Lodging Frequency
Save
When you Prepare BAS via QuickBooks you will see a step in the Wizard to enter the PAYGI amount now. If you have selected Monthly PAYGI and Quarterly BAS you will see the option to lodge IAS.