Verification is the artist's. The passport is yours: your name, your photo, and the artists you belong to with your role in each. Sign in with TAP and an app reads it, with nothing else to send.
One passport per person, whatever number of artists you work on. It lists the artists and your role in each, from your team memberships.
Everything happens on the Passport page in your account. TAP does the rest.
The passport says who you are and which artists you belong to. It says nothing else, and that is the point.
Free, like everything an artist gets. What the passport needs and what it shows: Your passport in the docs.
Sign in with TAP and an app knows which artists you belong to, and in which role.