Wow! that's a huge prize, congrats on your winning! Very lucky. Regarding to your question, It depends where country are you came from? I think there's a country who didn't collected any crypto winning taxes but just to make it clear, you can alao ask your local IRS to inquire about this. Having that 7 figures winning amount, I think It's better for you to report it and to pay your taxes in the most legal way so you can enjoy your winnings freely without doing tax evasion. Afterall, it's a money came from your betting prize, The tax you will pay is a meager amount for the amount of money you earned from gambling.