POST <your verify_url>
Content-Type: application/json
X-Verify-Secret: <secret>

{
  "code": "USER-ENTERED-CODE",
  "nonce": "a1b2c3d4...",
  "claimer": "f47ac10b-58cc-4372-a567-0e02b2c3d479"
}

curl -X POST https://your-site.com/redeem \
  -H 'Content-Type: application/json' \
  -H 'X-Verify-Secret: YOUR_SECRET' \
  -d '{"code":"ABC123","nonce":"a1b2c3","claimer":"f47ac10b-..."}'
# => {"verified": true}

POST https://modeloc.com/shared/<share_id>/callback
Content-Type: application/json

{
  "nonce": "a1b2c3d4...",
  "secret": "<secret>"
}