Signacore
You need the link from your email.
This address is where SignaCore documents are opened and signed, but every document has its own link. There is nothing to sign in to here, and no account to create.
Find the email
Look for a message from SignaCore with the subject Signature requested, sent by whoever asked you to sign. Check spam, promotions, and anything your organisation quarantines before assuming it never arrived.
If the link has expired
Signing links last 7 days. An expired one cannot be extended from here, and nothing you already entered is lost - ask whoever sent the document to send it again, which issues a fresh link.
If the code has expired
That is a different thing, and a smaller one. A verification code lasts 10 minutes, and you can ask for a new one from the signing page 60 seconds after the last.
The code always goes to the address the document was sent to. Forwarding the link does not move the code - that is deliberate, and it is what stops the link alone being enough to sign as somebody else.
Still stuck
The help centre covers the rest, and support@mysignacore.com reaches a person. Say which document you mean and we will reply as soon as we can, usually within 24 hours. Do not include a verification code in your email.