Unity STEP Importer is a Unity package that enables you to import STEP-models, extract their mesh, texture and hierarchy information and import it into Unity as GameObjects.
Download the package through the Window > Package Manager in the Unity Editor with Add package from git URL.... Using the URL https://github.com/FKI-HTW/UnitySTEPImporter.git#upm for the newest version, or https://github.com/FKI-HTW/UnitySTEPImporter.git#VERSION_TAG for a specific one. The available version tags can be found in Tags.