nostr:npub1m4333mvet9fad9slvyk6zrhvzx0ha0udv6047rfrwxva6jhfnw9qsd246h

Use bitcoin through Tor. It's not perfect but adds a layer of anonymity. They can know your wallet and address used to send receive but can't link it to you personally unless you use the wallet unblinded.

If you want much more solid anonymity then use Monero (also through Tor)