Sometimes a them does not have a separate menu structure for smaller screens. This module ensures that, with a self-imposed break point, you set the menu structure for smaller screens.
So I use sometimes Showcase Lite theme that has no responsive menu in the free version. We solve this by activating the module. In the settings you choose the menu style.
Important! Set the selector. This ID or class turns your menu into a new responsive menu. You have to search yourself (with the inspector of the browser) the selector of the menu.
The breakpoint you choose yourself.
For a wide screen ...
For a small screen.