Creating order in a Postman using BigCommerce API

Question

I'm trying to create an order in a Postman using BigCommerce API. I have already created a cart and checkout ID. While creating an order and putting in all the necessary details, I'm getting a 422 error status.

This is how I entered the Billing details:

{
  "billing_address": {
    "first_name": "Pushkar",
    "last_name": "Dutta",
    "street_1": "527 Abraham Tunnel",
    "city": "Austin",
    "state": "Texas",
    "zip": "78751",
    "country": "United States",
    "country_iso2": "US",
    "email": "pushkar.d@ignitiv.com"
  },
  "products": [
    {
      "name": "[Sample] Able Brewing System",
      "quantity": 1,
      "price_inc_tax": 10.25,
      "price_ex_tax": 10.25
    }
  ]
}

Error:

{
    "status": 422,
    "title": "The billing details for this order are incomplete.",
    "type": "https://developer.bigcommerce.com/api-docs/getting-started/api-status-codes"
}