One of QuickBooks' requirement for the integration to work is tax codes. There's a way to activate tax codes in your QuickBooks account even if your not yet registered.
Please set the appropriate tax code for your account and follow these steps:
*The steps show GST as an example.
Step 1: Setup/Activate GST (Tax code) in my account settings
Step 2: Create one invoice or expense (Set it to $1 for example)
Step 3: Select 'Out of scope GST'
Step 4: Go to my Advanced Account Settings
Step 5: Set my Default Tax Rate Selection to 'Out of scope GST' and you're done!
If you need help with anything we are here for you :-) Just message us in-app by clicking on the green chat icon on the bottom right hand side and one of our friendly staff will give you a hand.
Please note that different versions of QuickBooks have different options so it's better to seek support from QuickBooks customer service.