Taken to assume "100% anonymous" even from governments, those days are gone.
Even if many registered agents in the US don't ask for KYC (at least for forming LLCs), which does mean you can start a company there without providing genuine details, you lose anonymity if you ever want your company to access the financial systems of the world.
Solve your problem in a way that doesn't require anonymity, because that's practically unfeasible nowadays.