How to track order of newly created files in directory with fswatch

I need to monitor a downloads directory, and keep track of the order in which files were written to the directory. The only way I know this is possible in macos is fswatch, but the documentation seems quite sparse compared to inotifywatch on linux.

For example, if 001.jpg then 003.jpg then 002.jpg were downloaded to the directory (in that order), I would need a variable that looks like this: 001.jpg 003.jpg 002.jpg

I only need to monitor new files in this case, not modified files. For example, if 001.jpg is modified, it should not be moved to the end of the list.