When and if there are no index files in the directories, a directory listing is displayed instead.
If you do not want this behavior you can disable directory listing with the following in a .htaccess file.
Options -Indexes
This would result in any directory not containing valid index files (index.php, index.html, etc.) returning an access denied response if some one navigated to the URL https://swimisca.org/wp-content/uploads/2021/10/
( or any other URL with directory that has no valid index files).
