In nopCommerce, administration menu is build from the Sitemap.Configuration file which is located in Nop.Admin folder.
To do the same, you can use following sample code which you need to add in your plugins’ cs file. First, implement IAdminMenuPlugin intereface in your plugin main class. Then,
You can also put any security (ACL) logic to this method. For example, validate whether current customer has "Manage plugins" permission.
In version 2.00-3.50 you should do it the following way:
In the above code, you can find comments where you need to replace values depending on your requirements. Moreover, the above code also explains how you can add a child menu items inside main menu.