Op, the only way in which you can avoid paying tax from your bitcoin and crypto currency earning is for to relocate from your current country to country where taxes are not paid on crypto currency related activities such as Nigeria.
How do you know that crypto doesn't get taxed in Nigeria? Even if it was like that, with more and more regulations being enforced globally, things might change rapidly, especially so when it concerns taxes on cryptos. And then it also depends on what category they place crypto in. In Japan for example, you'll end up paying 55% in tax when it comes to amounts over $350k in their own fiat currency. In the US there are states where the property tax rates are insanely low, but on top of that you will also have to pay state tax, welfare tax, etc. If you calculate all these different tax levels, you'll come to a tax figure close to 40-50% in certain states. Crypto is a cash cow for the government, that's a fact.