Please go to your backend > Menus > Main Menu and Click on the "New" to create a new item.
Then, please select this "Menu Item Type"
II. CONFIGURATION:
After create this menu item, you need to pay attention to some tabs such as: Details and Basic Options.
Details:
Basic Options:
The meaning of "Use Global": If you select it, the option is applied according to the option in Components > TZ Portfolio Plus > Options > In the tab "General" and "Search".