Employee has changed email address

One of my employees has registered their account using their gmail address. They have lost access to this email account and have given me a new email account to update in the HR app. I have done so, but how can I send them a new request so they can get access to the HR app? it says in the user guide only the employee can update these settings. But in this case, they do not have access to the HR app using their old email address as they cannot remember their password and the password reset will go to their old email address even though I updated it as an employer on the app. How can we fix this?

No, you cannot fix it from your end, only your employee can try to change the registered email address. However, since the email is lost forever, then the next thing you could do now is to create another new employee and invite again.