Since Reverberate is not in the FX list try looking at Options->Preferences and select Plugins and VST in the left window. Add the location of the Reverberate.vst file to the VST Plug-in paths. It may be necessary to search for the file on a PC if you do not recall the installed location. With a Mac there's a standard location for VST plugins, Library/Audio/Plug-ins/VST.
With the new path included in the list click on Scan to find Reverberate.vst.