True anonymity is a high bar to meet while doing official financial business, one which I think is highly unlikely to achieve. I think you may have to settle for either being partially pseudonymous or simply deal with having to conduct business exclusively through anonymous cryptocurrencies, however impractical that may be.
Without any elaboration on how you’d do this, to me that sounds like fraud which is definitely illegal, risky, and (if using someone else’s info) unethical. I have heard of people creating business PayPal accounts so their names aren’t shown to others on the platform, which could give you some degree of pseudonymity.
But if PayPal and the government want to find who’s behind the account, they can obviously find you. You should also consider whether your true identity can be discovered through OSINT and if there’s anything you can do to mitigate it.