I am already having a menu built using KnpMenu in Symfony project. But, it is having just four childs meas four menu items. Now, I have to add dropdown. If anyone has any idea, please, comment. Please, help how to get its dropdown css, dropdown classses, how to customize it.
Reference - https://github.com/KnpLabs/KnpMenu
Dropdown can be added by adding child too the menu items in php file and for formatting use own class or bootstrap class.