You can send files for review directly from the Files tool either by manually selecting files and folders, or automatically by creating and applying review auto-triggers to folders.
You need View only folder permission or above to submit files for review.
Select one or more files from the files list and either:
in the action bar above the files list.Select Submit for review
Select the Approval workflow that you want to use.
If no workflows are available, an administrator can create approval workflows in Docs. See the Create and Edit Approval Workflows to learn more.
Enter a Review name.
If necessary, add more files and enter any notes you want to include. You can also edit the folder the files are copied to when the review is complete.

Click Submit to initiate the review.

Optionally, send an email notification to the reviewers, approvers, and(or) other project members to let them know the review is ready.
Review are listed in the Reviews tool in Docs, awaiting action by the reviewer or approver.
In Docs, you can also create and edit approval workflows, Review, and Approve Files and export a reviews report from the Reviews tool.