Hi neighborlee. I recently answered you over on the Answerhub (Datasmith options missing in 4.21 - Getting Started & Setup - Epic Developer Community Forums)
I’ll go ahead and add additional information here:
- If you are using the new UE 4.24 version, then Datasmith is automatically included in the engine, and enabled depending on the type of project you create. For other project types, it can also be enabled from the Edit > Plugins > Importers menu.
- If you are using UE 4.23 or earlier, then Datasmith exists as a separate plugin which can be downloaded from here: Unreal Datasmith in Code Plugins - UE Marketplace. The plugin will need to be installed to your engine version via the Epic Launcher.
- Both any scenario, if you are working with 3ds Max, SketchUp Pro, or Revit - you will also want to get the exporter plugins from here.