How can he sign his tracks with his pubkey?
those tracks are not signed by your pubkey 😕, if they had been you could have linked to your profile like
https://zapstr.live/npub1l2vyh47mk2p0qlsku7hg0vn29faehy9hy34ygaclpn66ukqp3afqutajft/tracks
Discussion
He can’t, that’s the point 😅
In Zapstr you can upload tracks with your key and own the track yourself