Restoring Clips Projects from iCloud

I was using an iPhone 6S and shot a video project in the app Clips. My phone may have automatically backed up the project on iCloud (As I can see Clips is taking up room in my iCloud Storage with one 300MB document). Afterward, I deleted Clips but keep the Clips documents on iCloud. Recently I started using an iPhone 12 mini and decided to download Clips again. When I open Clips I cannot see the projects restored. So here comes the problem: how do I restore my previous-backed-up projects from iCloud? Or maybe the document was not a video project.