*--captcha*::
The captcha token, required if registration failed with a captcha required error.
To get the token, go to https://signalcaptchas.org/registration/generate.html
+For the staging environment, use: https://signalcaptchas.org/staging/registration/generate.html
Check the developer tools for a redirect starting with signalcaptcha:// Everything after signalcaptcha:// is the captcha token.
=== verify