Lookup Manager allows to pick up data from external datasources. Following datasources can be used:
To start using Lookup Manager in Project Server 2010 open the “FluentPro LookupManager” SharePoint list (PWA→Site Actions→View All Site Content). Please note that you need to have permissions to do so.
To start using Lookup Manager in Project Server 2013 open the “FluentPro LookupManager” SharePoint list (PWA→Gear button→Site contents).
You will see an empty list where you can create your datasources.