same problem:
npx shadcn@latest add “https://v0.dev/chat/b/b_od0gFMX0vRw”
leads to>>>
Something went wrong. Please check the error below for more details.
If the problem persists, please open an issue on GitHub.
Unexpected token ‘<’, "<!DOCTYPE "… is not valid JSON
When you copy the command, it should include a ?token=asdf param that logs you in
Without that token, the URL resolves to a 4XX error page and the error you’re getting is it trying to parse that HTML instead of the JSON it’s expecting
now it’s work, seems like sometimes URI not present in copied url (via interface button - in top right corner)