Taxes for iatlian (EU) resident - how do they work?

Hey all,
I am trying to understand how taxation works for an italian (EU) resident.

I do have a TIN number as well as VAT number, but what exactly Spreadshirt has to deduct from my earnings?

I understand that this is the basic deduction: 15% withholding tax plus 5.5% solidarity surcharge on the withholding tax.

But what about VAT? In Italy we have a 22% tax on every transaction. Does Spreadshirt deduct that as well?
It’s not clear in the documentation.

Thank you for any help!