How to add your tracking page to the menu
From your Shopify admin dashboard go to Online Store -> Navigation.
On the Navigation page, click the title of the menu that you want to edit.
Click Add menu item.
Enter a title for the menu item, in this case, it can be "Track your order" or "Order tracking". This is what your users will see in the menu, so make sure it is descriptive.
In case your store is in another language, just type in the equivalent of "Track your order".
For example, if your store's language is Spanish, you can call this menu item: "Track your order".
Next, click the Link field, and then select add link here.
To get your tracking page link just add /apps/tracking to your store's URL address.
Click "Save menu".