You use the product_class field to add product class to your requests. It ca be for physical goods or shipping and other charges.

Physical Goods

To specify a good as a physical good, you can add product_class=P, as follows:

        "transaction_lines": [
            {
                "amount": 100,
                "custom_id": "",
                "ship_from_address": {
                    "country_code": "GB"
                },
                "description": "Product 1",
                "product_class": "P",
                "product_tax_code": {
                    "class": "TPP/Goods"
                }
            },

Shipping and Other Charges

Details about how to add the Product Class for shipping and other charges is provided in the Shipping and Other Charges topic.