AWS S3 Permissions for Download Monitor

I need to use Download Monitor with AWS S3 for my video subscription site due to the file sizes. What permissions do I need to set for 1) My S3 bucket and 2) for the individual video files? This tutorial has a list of the bucket permissions at 3:38 and file permissions at 7:08. I want to make sure the files are accessible to a user who clicks the Download monitor button, but inaccessible to just any user generally. Note, I’m already using a membership platform that integrates with Download Monitor, so people will have to pay to download the video. Thanks in advance for support!