how to count category->products which are related to the order

I have four tables Order, Category, Product, Order_Product

each product belongs to a category each order has many products

i save the order products in order_product table,

now in orderResource i want to have number of order->products in each category so OrderResource should have

data 
[
{
 category_name: 'something',
productsCount: 3,
},
{
category_name: 'somethingelse',
productsCount: 2
}
]

how to do so ?

Level 2

$categories= Category::withCount('orders')->get(); // Returns categories with number of orders count

create orders() function by following below relation

Level 2

$categories= Category::withCount('products')->get(); // Returns categories with number of products count

create products() function by following below relation

Please or to participate in this conversation.