1. You'll first need to have Blender Installed
2. Once you have installed Blender or if you already have it installed, open the application.
3. Import your usual model files via the import button in the file menu.
4. If your file correctly imports, go back to the file menu and select export.
5. Within the file type options, select gltf/glb.
6. Name and save project to the proper folder. Now, you have a glb that can be used for your AR projects.
Exporting GLTF Animations in Blender
Backfaces in Blender