Question: how to create usdz file?
Answer: Open the Vectary editor.
Create your 3D model or import your 3D file with drag and drop (OBJ, STL, GLTF, DAE, STEP and 60 more file formats).
Export it as a USDZ 3D file in the Export tab. ... 
You can also preview the USDZ on your iOS device by scanning the QR code.