My biggest concern about the stock tokenization platform is taxes?

Is there a master here to explain?
Because the tax system in the United States is very strict, stock gains are subject to capital gains tax, and there are also various other taxes such as inheritance tax.
If I buy stocks like Apple and Nvidia through a US stock platform, and then make money by selling high and buying low, who will help me pay taxes when I cash out my coins?
If no one helps me pay the taxes, then I assume it is trying to be clever with me.