Permalink Manager allows to either add or remove the trailing slashes from all WordPress permalinks. Based on your preference, in the plugin settings you can either:
- keep native settings
- force trailing slashes (and if needed auto-redirect permalinks without them) in all WordPress permalinks
- remove trailing slashes (and if needed auto-redirect permalinks with them) from all WordPress permalinks
The plugin filters $wp_rewrite->use_trailing_slashes property/variable, so all WordPress permalinks (not only the ones filtered with Permalink Manager) will be affected.
It is also possible to exclude the specific post types & taxonomies from Permalink Manager trailing slashes settings. Here you can find more information on how to do do.