Joan PC

Good afternoon, I am new to this, I have been investing in USDT and trading for a while, I made good profits, but when I tried to withdraw all my earnings, the company sent me an email saying that I have to pay 20% for income tax (depending on each country), and they attached the address for the tax domicile to make the deposit. Is this true, is it necessary? I have doubts...any knowledgeable person, please.