All user types (including collaborators) can assign files for review, and all user types can be assigned to review files. File Approvals are a part of the Wrike Proof add-on.
Use File Approvals when you have files that need to be reviewed and approved by teammates. Approvals help organize and bring transparency to the review process by allowing your team to keep track of:
What files need to be reviewed and approved.
Who's responsible for approving a file.
What each file’s review status is.
You can filter files according to their approval and guest review status, user(s) assigned as approvers, on their start or due dates, and more.