threejs-obj-space/js/three.js-master/utils/exporters/blender/README.md

Three.js Blender Export

NOTICE: The Blender exporter for the Three.js JSON format has been removed, to focus on better support for the glTF workflow. For recommended alternatives, see Loading 3D Models. The Three.js Object/Scene JSON format is still fully supported for use with Object3D.toJSON, the Editor, THREE.ObjectLoader and converters.

If you really need the Blender Exporter you can go back in time to r92.