This feature is only available to Publishers, GoProof Admins and Gatekeepers.

Step 1.
Access the proof via the link from your invitation email.

Step 2.
Click Collaborators in the side panel.

Step 3.
Type in the collaborator's email address in the email field or select from the list when provided.

The newly added collaborator will be emailed advising that there is proof ready for them to review.