Advanced Menu improves the top menu of OpenCart 2:
– Allow to click on menu item and go to the link of item intead of doing nothing.
– Add arrow to menu items which have sub-menu
– Add button to toggle sub-menu in mobile
Unzip the downloaded package
Use Extension Installer to install this extension vie_advanced_menu.ocmod.xml and go to Admin > Extensions > Modifications and click on Refresh button.
See this post for more details.