How to x-cart v5 remove parent category url from sub-category url?

[Oblong]

At www.cheapglasses.net, I have setup a main category called: Prescription Glasses, and its url is http://www.cheapglasses.net/prescription-glasses;
Under it I add a sub-category called: Womens Eyeglases, How to let this sub-category url be: http://www.cheapglasses.net/womens-eyeglasses , pls?

[Ocracoke]

You can do this for product pages (the "use_canonical_urls_only" setting in etc/config.php file), but not for subcategory pages, unfortunately.

; Use canonical URL for product page
use_canonical_urls_only = On