You can either resend the invitation email or you can copy the direct link to the case. You do this by clicking on the icon with the two squares to the right of the person. When you press the button, the link is automatically copied to your clipboard, after which you can paste the link and send it from your work email to the end user. This link is personal and can only be used by this end user on the case in question. The link is the same as that sent in the invitation email.
