Access to original files

I have a file in the sample location: https://mydomain.com/wp-content/themes/uploads/2025/04/my_file.jpg (it’s file with watermark)

When I modify this URL like this: https://mydomain.com/wp-content/themes/uploads/iw_backup/2025/04/my_file.jpg I have orginal file without watermark.

If someone has basic knowledge, they are able to download original files without watermarks from my site. Will securing the htaccess of the iw_backup folder solve the problem?