An Integration for Cityworks Server license is required. Working with documents in OnBase (storage, retrieval, etc.) requires a valid OnBase Client license.
The Integration for Cityworks Server license includes the Plan Review Toolkit add-on license including REST API.
Check your current licensing status by selecting from the Configuration module.
Additionally, if using Trimble Unity or Cityworks with OnBase Electronic Plan Review, a Plan Review Named User or Plan Review Concurrent Client is required to use Plan Review.