Normally you give DOKKA the invoice amount and tax rate, and DOKKA does the rest. Sometimes, the tax/VAT amount comes out differently than the amount printed on the invoice. For regulatory reasons, it needs to match. Or maybe you have a different reason to modify the VAT amount.
Now you can! (For now this option is only available in QBO.)
To allow this, first click on the gearwheel to enter the Settings screens. Next Click on Integrations and the name of your accounting software. Additional options will appear. Find the option to Override tax amounts and toggle it on.
Go back to the Workspace and open a document. As you complete the bookkeeping form, the Tax amount will be gray. You can leave this amount or modify it by typing or with the Drag&Drop feature.
The value in the Tax Amount field will be used in the total calculations at the bottom of the form and posted into your accounting system.