Please access the portal with the same email address that was used to send you the invitation and add candidates with the + button. After a candidate has been submitted by you, editing is not possible anymore.
Your candidates list
Use the candidates list to keep track of the current recruiting state of your candidates. You will see the pipeline stage as well as a final rejection. So there is no need to try to call someone to get an update.
Communication with the hiring team
From the candidate's profile on your portal, you will be able to leave comments to the hiring team, as well as see what any member of the hiring team shares with you regarding this candidate.