Can I assign a screen in Workflow to an external reviewer who isn't a collaborator on the prototype? V6

At this time, the assignee of a screen must be a collaborator or member of the prototype. External reviewers that aren’t explicitly members of the prototype won’t be able to be assignees. If you send a share link to an external reviewer when you’d like them to review rather than having them login to view the prototype, then they’re an external reviewer and won’t be able to be an assignee.

We recommend using the “Needs Review” status to track screens that require external review.