In order for the package to be included in the build, add the FBXSDKRUNTIME define to Edit > Project Settings. NOTE: The FBX SDK bindings are Editor only by default and will not be included in a build. However, there are two file formats that do not use FBX as an intermediary: SketchUp and SpeedTree.For more information about importing these file formats, see the SketchUp Settings and SpeedTree topics. These package versions might not be safe to use in production with Unity version 2020.1: Documentation location: The FBX SDK bindings can be executed during gameplay allowing import and export at runtime. Note: This section provides information about proprietary file formats that use FBX conversion. Version information Experimental or in preview for Unity In particular, this round-trip workflow enables you to export Unity Scenes to FBX files, import them into Autodesk® Maya®, Autodesk® Maya LT™, or Autodesk® 3ds Max® using an artist-friendly interface, export Unity-ready FBX geometry and animation, and safely merge your changes back into those Assets to continue your work in Unity. Select whether to export Animation, Deformations, Skins, Morphs according to your needs. The Unity FBX Exporter package makes it easy to send geometry and animation to any application that supports the FBX format and send them back to Unity with minimal effort. Setting the FBX export options Check your FBX export settings: Check each setting in the export dialogue of your 3D modeling application so that you know what to match up the FBX import settings in Unity.

Export unity scene to fbx