The Joomla menu system includes the menu's parent name in the URL structure for sub-menu items as follows: https://www.mysite.com/parent/page
I'd like to remove the parent as follows: https://www.mysite.com/page
How can that be done?
Can’t be done with core, but there are numerous extensions that allow uri rewriting. The simplest one for your request is https://extensions.joomla.org/extension/direct-alias/
A "clean" way of addressing this problem from within the Joomla is to create the child menu item in a hidden menu, and then reference (in the real menu) the child menu item using a menu item of type "Menu Item Alias". I'm usually against all those URL rewriting plugins as they generally cause more harm than good, especially on high traffic sites.