Type the code printed on the document. No account needed.
Spaces, hyphens and lower case are fine — it is the same code however it was written down.
Every document signed through SignSealer comes with a certificate of completion. It says who signed, when, and the fingerprint of the exact text they agreed to, and it carries a code. That code opens the record SignSealer keeps of the signing.
This page compares the two. If the certificate still matches the record, nothing about the signing has changed since it was issued. If it does not, the page says what differs. If a business has removed the people's details under its retention policy, the page says that too, and the fingerprint, the times and the trail still match.
Nobody needs an account to check: not you, and not the person who signed. More on the evidence behind a signature.