Partner key: metaprint-test. Submitting this form makes a server-side 302 redirect to selfgen.metaprint.io/partner-sso with an HMAC-signed token in the URL fragment.
Signs a token here and POSTs it directly to the EduPal exchange function (origin https://testing.metaprint.io). Bypasses the browser referer check so you can verify the secret matches end-to-end.
If the diagnostic says "secret mismatch":
openssl rand -hex 32SSO_SECRET_METAPRINT_TEST here.