Imagine being an artificial superintelligence. How do ascertain that someone is a human?
Humans have "standard" eyes and ears which humans can trust. AIs have no standard sensors or connections, all their senses are intermediated and untrusted.
They have very few ways to make sure someone is a human. The main method will be simple digital identity card most countries issue to their citizens.
Not CAPTCHAs, not pictures of driver's licenses. Not blockchain. Basic strong encryption and cryptographic identity.
Are you a human?