Ok, a few different compatibility issues to solve for it to be compatible with 3DObject.
1. The format needs to be gltf embedded, not gltf with an external bin file. You can use blender to load gltf with an external bin and export with gltf embedded.
2. The texture must all be in one png file, in the fnaf file there is a texture per color, they must all be baked together into one file.
3. The texture file resolution must be larger than the project sprite sheet size, so it the single baked texture must be larger than that (you can set the project spritesheet size to 512 and then size the texture resolution to be 512x512.
These requirements are listed in the details for the plug-in on itch, so I suggest reviewing that again.
Another great resource is the video on this site which explains how to export gltf embedded and how to bake and export textures.