Enabling the custom menu override in Site configuration allows you to override the automatic generation of the menu, and specify the items that it should contain manually.
Set the “use_custom_menu” flag in the Site configuration to true.
In your site configuration, set the “custom_menu” property to be an array of objects. Each object should have atleast two properties:
Optionally, you can also define a “meta” property, which is an arbitrary JSON object that will be made available to the theme on each menu item. This can be used to hold additional information, for example, what icon to display next to the link.