https://community.vercel.com/t/error-when-adding-to-codebase-via-shadcdn/4991
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