To embed a 3D image on your Shopify homepage, you can use a third-party app or a custom solution. One option is to use the Shopify 3D Warehouse app, which allows you to embed 3D models on your store's pages. Another option is to use a custom solution, such as creating a 3D model and embedding it using HTML and CSS.
In your post, you mentioned that you tried using the Shopify 3D Warehouse app but were experiencing issues with it. You can try troubleshooting the issues by checking if the app is compatible with your theme and if there are any conflicts with other apps or code on your site.
Alternatively, if you are comfortable with HTML and CSS, you can try creating a custom solution for embedding the 3D image on your homepage. You can create a 3D model using software such as Blender or SketchUp, then use HTML and CSS to embed the model on your site.