Verify

GET https://api.tyntec.com/silent-auth/v1/oauth2/authorize
  ?response_type=code
  &client_id=client
  &state=xyz12345
  &scope=openid%20tt%3Aphone_verify
  &redirect_uri=https%3A%2F%2Fclient.example.com%2Fcallback
  &login_hint=301234567890

HTTP/1.1 302 Found
Location: https://client.example.com/callback?code=<code>&state=xyz12345

HTTP/1.1 302 Found
Location: https://client.example.com/callback
  ?error=<error>
  &error_description=<error_description>
  &state=xyz12345