Using <model-viewer> While Keeping CAD files Non-Downloadable

I am looking to self-host CAD files (e.g. .glb files) on a private server (i.e. GCS, AWS S3, Google Drive, etc.) and display them on my Squarespace website for use in my portfolio using <model-viewer>. However, I do not want users to be able to download these CAD files unless I specifically intend for them to. For example, in the setup I currently have implemented, a user could inspect the <model-viewer> and find the URL that points toward the CAD file on my GCS bucket, which is currently fully public.

How can I keep the <model-viewer> functionality while keeping the CAD files non-downloadable?