Joomla works with internal (for example
/index.php?option=com_content&view=article&id=42) and external SEF URLs (
/some-name). The SEF URLs are created via the menu, and the "alias" from each Menu Item and/or article is used to create the URL.
A proper way to create SEF URLs in Joomla components/modules/plugins is to use the JRoute method (or more modern: Route + namespace
If your module has been programmed in a proper way, it will use that (J)Route method. And it will use the menu structure + "alias" of menu items or articles.
In recent versions of Joomla 3 + 4 you can search all menu items for alias "car-rental-branch" and change the alias to "car-rental". Or if it's an article that does not have a menu item, check the
Content > Articles.
When you change the alias of a menu item, the URL will change accordingly. So you might want to add a redirection in
Components > Redirects to redirect traffic on the old URL to the new URL.