So basically this can download thumbnails from any scratch project. I havent made a Github Sites for it so you can just open it on this link: https://scratch-thumbnail-downloader.rohanboutelle.repl.co/
Go to the link that is above Then go to the Scratch project that you want to get the thumbnail from and copy the project ID
Once you have done that you have to paste in the Project ID And then press the "Get Thumbnail" button