Go to https://www.genarate.com and log in.
You can either choose to work with an existing project or set up a new one. Within the project you can decide whether to create a new WonderPage or use an existing one.
After you have defined a target image please click on the “3D Model” icon in the toolbar on the left and then browse/insert for the 3D Model you want to place in the Designer panel (possible formats: fbx, gltf, glb).
The 3D object shows up on top of the target image. In the settings panel on the right, you can modify various settings like size, rotation, autoplay, etc.