Also note that many of thomthom's extensions need you to install his TT_Lib 'helper' file...
https://sketchucation.com/pluginstore?pln=TT_Lib
So download and install that too...
Restart SketchUp after installing any Lib's RBZ so that everything gets properly synced...
Fredo's extensions are another example where a Lib needs to be installed too...