Enabling FBX Integration

Install FBX Exporter 2.0.1 or newer via Package Manager.
Add the following dependencies to Unity.ProBuilder.AddOns.Editor.asmdef in the "references" array:
- "Autodesk.Fbx"
- "Unity.Formats.Fbx.Editor"
Open Project Settings and add PROBUILDER_FBX_2_0_1_OR_NEWER to the Scripting Define Symbols field.