It doesn't matter where you live, Itch.io is a USA platform, and by law, each transaction made from the USA is subject to a withholding tax, in your case 30%

The good thing is that it is only for transactions made from the USA, if someone buys your game from somewhere else, for example, Germany, then they do not apply that withholding tax.

IMPORTANT, this value is calculated and reflected only at the moment you request a payment from Itch, before that, it only shows you a reference value.

Example. You sign up today, tomorrow you sell a game for 10 dollars in the USA and another for 10 dollars in Germany.

Itch will tell you that you sold 20 dollars, but you only have 6 available. Those 6 are a reference value that considers a 30% withholding tax on all sales.

When you request payment, only then is the exact calculation made.

Which in the previous example should be more less:

10 from USA - 30% tax - 10% Itch - credit card commission = 5.5
10 from Germany - 10% Itch´ - credit card commission = 8.5
Total = 14

Remember that validating the tax interview has a value of 3 dollars that are deducted from your first payment.