To add items to a menu, you need to make sure that item is assigned to a category, and that category needs to be applied to the desired menu. Follow the steps below to confirm this, and add items to your menu!
Navigate to the "Menu Admin" section, by clicking the "Menu Icon" that's located on the left side of the screen.
Click on the "Categories" tab, located at the top of the screen.
Click on the category that you would like this item added to, and that is currently applied to your menu.
From here, verify that the desired item is applied to the category. If it isn't, click on the blue "Add Menu Item" button and select the desired item to add it to your category. Click "Save".
Click on the "Menus" tab located at the top of the screen, and then select the menu that you want to add items to.
You will now see a list of different categories currently applied to the menu. If you see the category your item is located in, click on the blue "Edit Category" button. If you don't see your category, select "Add Category".
A pop-up will appear with your "Edit Category" options. Click on the "arrow' > icon that is located to the right of your category's name. Find your new item in the list, and check the box next to its name.
You can now click the "Save" button located at the top right of the screen. You can either publish your menu directly from this page or navigate back to your "Menus" tab to publish.
Note: These changes will not reflect on the menus your guests can see until the menu has been published.