Hi Ingrida,
I see the importance of having the gross amount instead of the net value of your transactions for VAT reporting. I recommend checking this with OneSaas since we have no control over the amount of the transactions sent by third-party apps.
On the other hand, if you want to check out some references about VAT, you can follow this link: https://intuit.me/3OVpvzW.
I'm just right here if you have more questions about QuickBooks. Have a good one!