What are you talking about? Someone is asking you to pay taxes before you can withdraw money (btc) from an account? These kind of pay us first things tend to be scams, designed to siphon money from folks through slick promises. you're a fool if you've already paid any money to them.
I wish I could say otherwise, but chances are you'll never see those funds again if you already sent them over. My advice? Don't send anything else their way and walk away and take it as a tough lesson. Going forward, be very wary of platforms asking for upfront fees like that. Legit ones typically dont operate that way.